The angles that satisfy the equation are three! So what do you want?
No! Not just three! Infinite!
I added the reply above to draw attention to the fact that there is a double post and the question is already answered - just follow the link above!
As I already had written that there is an infinite number of angles satisfying the equation. Prime is just showing the three in a predefined range (-pi/2; pi/2]. We could change that range using the assume command.
I also already suggested assigning the result to a variable and accessing the individual elements along with some other ways to get single numeric values.
Thanks Werner for the clarification. However, perhaps "kenan2" did not know how to highlight the individual elements of the vector, in this case the individual angles .... so I have calculated three roots as an example ....
