The value π/12 is a solution to the equation 2 cos2 (4x) - 1 = 0. True or false?
We will use trigonometric identity to solve this question.
2cos2(4x) - 1 = cos(8x)
Substitute π/12 for x in the above equation.
cos(8 × π/12) = cos(2π/3)
= cos(π - π/3)
= - cos(π/3)
= - 1/2
This is not equal to 0.