Question 1205877


The secant function was defined by the reciprocal identity

sec(x)=1/cos(x)

the secant function is {{{undefined}}} when the cosine is {{{ 0}}}, leading to vertical asymptotes at  {{{pi/2}}}, {{{ 3pi/2}}}, etc


{{{pi/2 = 90}}}°
{{{ 3pi/2=-90}}}°


answer:
D. Because the secant function is undefined at {{{90}}}° and {{{-90}}}°