# please guide me how to make plot from –pi to pi.

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Saleh on 18 Oct 2022
Commented: Saleh on 18 Oct 2022
in this equation
where k = 6+ 6, and the size = 30+ 9.
The plot should be from –pi to pi
X = size*cos(kt)*cos(t).
Y = size*cos(kt)*sin(t).
i use to make it like this but it gives me errors it still asks me about t is undefined
k = 6 + 6;
size = 30 + 9;
X = size * cos (k*t) * cos(t);
Y = size * cos (k*t) * sin(t);

Torsten on 18 Oct 2022
k = 6 + 6;
size = 30 + 9;
t = linspace(-pi,pi,1000);
X = size * cos (k*t) .* cos(t);
Y = size * cos (k*t) .* sin(t);
plot(X,Y)
Torsten on 18 Oct 2022
Saleh on 18 Oct 2022
i should make table and graph as i want semester marks as per the table suing either stem or bar function. The graph should be entitled “Spring Semester Marks”, with x and y axis labelled. Customize your graphs to be as unique as possible
title ('Spring Semester Marks')
xlable('Spring Semester Marks')
ylable('Spring Semester Marks')
patients = table(booksname,1,2,3,4)
is it like this ?

David Hill on 18 Oct 2022
k = 12;
size = 39;
X =@(t) size * cos (k*t) .* cos(t);
Y =@(t) size * cos (k*t) .* sin(t);
t=-pi:.01:pi;
plot(t,X(t),t,Y(t))
Image Analyst on 18 Oct 2022
Except that they should not use size as the name of a variable.

Image Analyst on 18 Oct 2022
Edited: Image Analyst on 18 Oct 2022
Try this:
t = linspace(-pi, pi, 1000);
period = pi/2;
amplitude = 39;
k = 12;
X = amplitude * cos (2 * pi * t * k / period) .* cos(2 * pi * t / period);
subplot(3, 1, 1);
plot(t, X, 'b-', 'LineWidth', 2);
grid on;
title('X')
Y = amplitude * cos (2 * pi * t * k / period) .* sin(2 * pi * t / period);
subplot(3, 1, 2);
plot(t, Y, 'r-', 'LineWidth', 2);
grid on;
title('Y')
subplot(3, 1, 3);
plot(X, Y, 'm-')
axis equal
title('Y vs. X')
Saleh on 18 Oct 2022
thank you very much i appreciate it