Here is a question, I've got an answer to it but I think its wrong

a) prove that (done)

b) verify that

is a solution to the equation

Does this rearrange to, using part (a), so, , which is correct??

c) Using your result in part (a), or otherwise, find the other two solutions, , of the equation using

For this I said that this meant that and the inverse tan of 0 = 0

So, using the general solution for tan, and the fact that

I got the answers 0 and 360, but I'm doubtful as the range is with no 'greater/less than or equal to' in there??