solving a trig equation

Hi guys,
in the question blow ,once you've find the value inside the bracket, do you have to divide it by two and then take away 75 from it?

Yep. You need to adjust your range (times it by 2 then add 75 to it). Then inverse tan the +/- root 3 and find all possible solutions in the new range. Then divide by two and take away 75 and that should give you all the solutions in the original range.

one of the answers is 22.5 , i've found out that inside the bracket s 60 but if i divide 60 by 2 and take away 75 from it wouldn't give 22.5

You should minus the 75 first, then divide by 2. Remember tan(x)=tan(180+x)