# Math Help - Help Checking Answers for Trig Expression.

1. ## Help Checking Answers for Trig Expression.

Found the solution, but just want to have some help verifying.
Note the restriction on Arccos. My answer was no solution as the whole thing in brackets was outside of the domain of arcsec.
1) Find all exact expressions, if any, of the following expression:

2. Originally Posted by mad_munky838
Found the solution, but just want to have some help verifying.
Note the restriction on Arccos. My answer was no solution as the whole thing in brackets was outside of the domain of arcsec.
1) Find all exact expressions, if any, of the following expression:
Well:

(cos(x)+sin(x))^2 - 2 cos(x) sin(x) = 1

so:

acos( sqrt[(cos(x)+sin(x))^2 - 2 cos(x) sin(x)] ) = acos(1) = 0

and there is no real angle with sec of 0, so there is no solution

RonL

3. Alright! Thanks