{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-05-26T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":43213,"title":"Create tangent function out of sine function only","description":"Please don't use cosine and tangent functions","description_html":"\u003cp\u003ePlease don't use cosine and tangent functions\u003c/p\u003e","function_template":"function y = TANGENT(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('TANGENT.m');\r\nassert(isempty(strfind(filetext, 'tan')),'tan() forbidden')\r\nassert(isempty(strfind(filetext, 'cos')),'cos() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\t\r\n%%\r\nx = pi/4;\r\ny_correct = 1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = -pi/4;\r\ny_correct = -1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":8,"comments_count":1,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":117,"test_suite_updated_at":"2016-10-29T16:48:35.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T10:03:26.000Z","updated_at":"2026-02-10T11:22:23.000Z","published_at":"2016-10-08T10:03:26.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use cosine and tangent functions\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43211,"title":"Create tangent function out of sin and cos","description":"Please don't use tan(x) directly","description_html":"\u003cp\u003ePlease don't use tan(x) directly\u003c/p\u003e","function_template":"function y = TANGENT(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('TANGENT.m');\r\nassert(isempty(strfind(filetext, 'tan')),'tan() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/4;\r\ny_correct = 1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = -pi/4;\r\ny_correct = -1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":8,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":120,"test_suite_updated_at":"2016-10-29T16:49:35.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T09:59:26.000Z","updated_at":"2026-02-11T18:05:07.000Z","published_at":"2016-10-08T09:59:26.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use tan(x) directly\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43210,"title":"Create sine function out of cosine","description":"Please don't use sin(x) directly","description_html":"\u003cp\u003ePlease don't use sin(x) directly\u003c/p\u003e","function_template":"function y = SIN(x)\r\n  y = x;\r\nend","test_suite":"filetext = fileread('SIN.m');\r\nassert(isempty(strfind(filetext, 'sin')),'sin() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/2;\r\ny_correct = 1;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi;\r\ny_correct = 0;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n%%\r\nx = 1.5*pi;\r\ny_correct = -1;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n","published":true,"deleted":false,"likes_count":9,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":107,"test_suite_updated_at":"2016-10-29T16:51:13.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T09:56:16.000Z","updated_at":"2026-02-17T08:29:00.000Z","published_at":"2016-10-08T09:56:16.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use sin(x) directly\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43212,"title":"Create tangent function out of cosine only","description":"Please don't use tangent and sine functions","description_html":"\u003cp\u003ePlease don't use tangent and sine functions\u003c/p\u003e","function_template":"function y = TANGENT(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('TANGENT.m');\r\nassert(isempty(strfind(filetext, 'tan')),'tan() forbidden')\r\nassert(isempty(strfind(filetext, 'sin')),'sin() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/4;\r\ny_correct = 1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = -pi/4;\r\ny_correct = -1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":9,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":96,"test_suite_updated_at":"2016-10-29T16:48:08.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T10:01:45.000Z","updated_at":"2026-04-16T05:02:46.000Z","published_at":"2016-10-08T10:01:45.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use tangent and sine functions\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43209,"title":"Create cosine function out of sine","description":"Please dont use cos(x) directly","description_html":"\u003cp\u003ePlease dont use cos(x) directly\u003c/p\u003e","function_template":"function y = COS(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('COS.m');\r\nassert(isempty(strfind(filetext, 'cos')),'cos() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 1;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/2;\r\ny_correct = 0;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi;\r\ny_correct = -1;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)\r\n%%\r\nx = 3*pi/2;\r\ny_correct = 0;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":10,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":118,"test_suite_updated_at":"2016-10-29T16:52:36.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T09:54:00.000Z","updated_at":"2026-02-18T14:22:37.000Z","published_at":"2016-10-08T09:54:00.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease dont use cos(x) directly\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"problems":[{"id":43213,"title":"Create tangent function out of sine function only","description":"Please don't use cosine and tangent functions","description_html":"\u003cp\u003ePlease don't use cosine and tangent functions\u003c/p\u003e","function_template":"function y = TANGENT(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('TANGENT.m');\r\nassert(isempty(strfind(filetext, 'tan')),'tan() forbidden')\r\nassert(isempty(strfind(filetext, 'cos')),'cos() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\t\r\n%%\r\nx = pi/4;\r\ny_correct = 1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = -pi/4;\r\ny_correct = -1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":8,"comments_count":1,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":117,"test_suite_updated_at":"2016-10-29T16:48:35.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T10:03:26.000Z","updated_at":"2026-02-10T11:22:23.000Z","published_at":"2016-10-08T10:03:26.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use cosine and tangent functions\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43211,"title":"Create tangent function out of sin and cos","description":"Please don't use tan(x) directly","description_html":"\u003cp\u003ePlease don't use tan(x) directly\u003c/p\u003e","function_template":"function y = TANGENT(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('TANGENT.m');\r\nassert(isempty(strfind(filetext, 'tan')),'tan() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/4;\r\ny_correct = 1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = -pi/4;\r\ny_correct = -1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":8,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":120,"test_suite_updated_at":"2016-10-29T16:49:35.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T09:59:26.000Z","updated_at":"2026-02-11T18:05:07.000Z","published_at":"2016-10-08T09:59:26.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use tan(x) directly\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43210,"title":"Create sine function out of cosine","description":"Please don't use sin(x) directly","description_html":"\u003cp\u003ePlease don't use sin(x) directly\u003c/p\u003e","function_template":"function y = SIN(x)\r\n  y = x;\r\nend","test_suite":"filetext = fileread('SIN.m');\r\nassert(isempty(strfind(filetext, 'sin')),'sin() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/2;\r\ny_correct = 1;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi;\r\ny_correct = 0;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n%%\r\nx = 1.5*pi;\r\ny_correct = -1;\r\nassert(abs(SIN(x)-y_correct)\u003c0.01)\r\n","published":true,"deleted":false,"likes_count":9,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":107,"test_suite_updated_at":"2016-10-29T16:51:13.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T09:56:16.000Z","updated_at":"2026-02-17T08:29:00.000Z","published_at":"2016-10-08T09:56:16.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use sin(x) directly\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43212,"title":"Create tangent function out of cosine only","description":"Please don't use tangent and sine functions","description_html":"\u003cp\u003ePlease don't use tangent and sine functions\u003c/p\u003e","function_template":"function y = TANGENT(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('TANGENT.m');\r\nassert(isempty(strfind(filetext, 'tan')),'tan() forbidden')\r\nassert(isempty(strfind(filetext, 'sin')),'sin() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 0;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/4;\r\ny_correct = 1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)\r\n%%\r\nx = -pi/4;\r\ny_correct = -1;\r\nassert(abs(TANGENT(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":9,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":96,"test_suite_updated_at":"2016-10-29T16:48:08.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T10:01:45.000Z","updated_at":"2026-04-16T05:02:46.000Z","published_at":"2016-10-08T10:01:45.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease don't use tangent and sine functions\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"},{"id":43209,"title":"Create cosine function out of sine","description":"Please dont use cos(x) directly","description_html":"\u003cp\u003ePlease dont use cos(x) directly\u003c/p\u003e","function_template":"function y = COS(x)\r\n  y = x;\r\nend","test_suite":"%%\r\nfiletext = fileread('COS.m');\r\nassert(isempty(strfind(filetext, 'cos')),'cos() forbidden')\r\n%%\r\nx = 0;\r\ny_correct = 1;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi/2;\r\ny_correct = 0;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)\r\n%%\r\nx = pi;\r\ny_correct = -1;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)\r\n%%\r\nx = 3*pi/2;\r\ny_correct = 0;\r\nassert(abs(COS(x)-y_correct)\u003c0.01)","published":true,"deleted":false,"likes_count":10,"comments_count":0,"created_by":13865,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":118,"test_suite_updated_at":"2016-10-29T16:52:36.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2016-10-08T09:54:00.000Z","updated_at":"2026-02-18T14:22:37.000Z","published_at":"2016-10-08T09:54:00.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003ePlease dont use cos(x) directly\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"errors":[],"facets":[[],[{"value":"easy","count":5,"selected":false}]],"term":"tag:\"trigonometric function\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}