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 :
now arent I supposed to do the following ? :
So the solutions are
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