How to get 2 angle values for an asin?

18 views (last 30 days)
Hey guys, I'm trying to solve for 2 angles that have the same sine value.
i.e. if x = asin(0.5), then x could be 30 degrees or 150 degrees.
I can't get this to come out though.
tried declaring a 1x2 symbolic variable x: [x1,x2], but if I try:
S = solve('x = asin(0.5)',x)
Then what I get out is:
x = 0.52... (30 degrees)
x1 = 0
x2 = 0
Can anyone help me out here? What am I doing wrong?
Thanks,
Joshua

Accepted Answer

A Jenkins
A Jenkins on 19 Jan 2015
>> syms x
>> solve('0.5 = sin(x)',x)
ans =
0.52359877559829887307710723054658
2.6179938779914943653855361527329
  3 Comments
A Jenkins
A Jenkins on 19 Jan 2015
arcsin is defined to only return the principal value. The documentation says:
For real elements of x in the interval [-1,1], asin(x) returns values in the interval [-pi/2,pi/2]. For real elements of x outside the interval [-1,1] and for complex values of x, asin(x) returns complex values.

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!