How do you find the critical points when Tan (x) is equal to zero? Please provide a descriptive explanation because I don't understand. Thank You

X = 7. g(x) = sec(x), 3 TT open interval 2 2 (noendpoints gi(x ) = secx)tan(x) = 0 to check sec ( x) = 0 tan ( x ) = 0 glo) =1 gur)=-1 never X = 0 , TT g' (x)