Question

Please help me with this problem.

Answer 1

Explanation:

`cos(x + 45 \degree) + cos(x - 45 \degree) = √(2) \\ cosx \: cos45 \degree - sinx \: sin45 \degree \\ + cosx \: cos45 \degree + sinx \: sin45 \degree = √(2) \\ 2cosx \: cos45 \degree = √(2) \\ 2cosx * (1)/( √(2) ) = √(2) \\ 2cosx = √(2) * √(2) \\ 2cosx = 2 \\ cosx = (2)/(2) \\ cosx = 1 \\ cosx = cos \: 0 \degree \\ \huge \red{ \boxed{ x = 0 \degree}} \\`