Answer:
D) undefined
Step-by-step explanation:
we would like to simplify the following
[tex] \displaystyle \sec \left( \frac{\pi}{2} \right) [/tex]
remember that, sec is the recipocal of cos
so,
[tex] \displaystyle \frac{1}{\cos \left( \frac{\pi}{2} \right) }[/tex]
by unit circle we acquire
[tex] \displaystyle \frac{1}{0}[/tex]
remember that, dividing by 0 is undefined
hence,
[tex] \displaystyle \sec \left( \frac{\pi}{2} \right) =\rm undefined [/tex]
