Hello,

A question says solve with no definite domain

Now I know how simple this is ..

But in class the teacher started explaining some weird stuff I couldnt understand.

Anyway, I know that I do :

ill get

now arent I supposed to do the following ? :

So the solutions are

and

Is the answer correct ? or am I doing something wrong :S

My teacher presented positive answers (+60) and not -60..

and in Wolfram Alpha, the answers are 120 and 60 ..

Please explain why

Thanks !!