cos (6x - π/2) = 0 6x - π/2 = π/2 6x = π x = π/6 → This is the first positive asymptote
The period of f(x) = sec x is 2π. So the period of h(x) = 2π/6 = π/3 There are 2 asymptotes in each period of the secant function, so h(x) has an asymptote every π/6.