Question

Solve the equation for [0,2pi]
cos2x=1/sqrt2

Answer 1

`cos(2x) = (1)/(√(2))`

`cos(2x) = (1)/(√(2)) * (√(2))/(√(2))`

`cos(2x) = (√(2))/(2)`

`cos(2x) = cos(45)`

`cos(x) = cos(22.5)`

`x = 22.5`