Question 936951
 {{{sec(-15*pi/4)  = sec(15*pi/4)}}}
  as {{{sec(-theta) = sec(theta)}}}
{{{ sec(15*pi/4)  = 1/cos(15*pi/4)}}}
                   ={{{ 1/cos(675)}}}
                      ={{{ 1/cos(720-45)}}}
                         ={{{1/cos(45)}}}
                   {{{cos(45)= 1/sqrt(2)}}}
                         = {{{1/(1/sqrt(2))}}}
                               ={{{ sqrt(2)}}}
                           
Result : {{{sqrt(2)}}}