Question

f (x) = 1 / cos (x-P/3)

Answer 1

$cos(x-frac{pi}{3})ne 0\x-frac{pi}{3}ne frac{pi}{2}+pi n,;; nin Z\xne frac{pi}{3}+frac{pi}{2}+pi n,\xne frac{5pi}{6}+pi n$