Question

The value pi/12 is the solution for the equation 2 cos^2 (4x) - 1 = 0 : true or false

Answer 1

`2 \cos ^(2) (4x) - 1 = 0 \\ \cos ^(2) (4x) = (1)/(2) \\ \cos(4x) = \sqrt{ (1)/(2) } \\ 4x = { \cos }^( - 1) ( \sqrt{ (1)/(2) } ) \\ x = \frac{ { \cos}^( - 1) ( \sqrt{ (1)/(2) } )}{4} \\ x \isnt \: (\pi)/(2)`