solving identities

To solve and identity you must use the identity formulas. How ever the biggest catch is unlike simplifying you cannot cancel anything. Only rearange, replace, and factor while solving these equations. Once you get it down to two or one simple trig functions you solve it using the 4 quadrants. Once you get two or four answers you convert them or leave as either radians or degrees as told by the problem.
Here are some identities that can be found when solving:

Pythagorean
sin^2x+cos^2x=1 tan^2x+1=sec^2x cot^2x+1=csc^2x

Cofunction
sec x(90-0)=csc x csc x(90-0)=sec x
tan x(09-0)=cot x cot x(90-0)=tan x
sin x(90-0)=cos x cos x(90-0)=sin x

Recipricol
sec=1/cos csc=1/sin cot=1/tan

EX1 solve square root of cos x(90-0) 1/2 o360
1. use identity from cofunction cos x(90-0)= sin x
so it equals square root of sin 1/2
2. sin 1/2 is on trig chart. It equals 30 degree.
3. since its square root it means + and - so we must find both positive and negative quadrants (find all 4 quadrants)
4. first quad 30
seond quad -30+80=150
third quad 30+80=210
fourth quad -30+360=330
5. the directions are in degrees so answer stays in degrees. you are done