Question

Find all the values of x (where 0 < or equal to x and x < pi/2) in terms of pi for which cos(6x)=0

Answer 1

cos(6x) = 0
cos⁻¹[cos(6x)] = cos⁻¹(0)
6x = 90
6 6
x = 15°
x = ¹/₁₂π radians

cos(6x) = 0
cos⁻¹[cos(6x)] = cos⁻¹(0)
6x = 270
6 6
x = 45
x = ¹/₄π radians

cos(6x) = 0
cos⁻¹[cos(6x)] = cos⁻¹(0)
6x = 450
6 6
x = 75
x = ⁵/₁₂π radians