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

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