Is cos piex/2 continuous or discontinuous?

Question

I need to justfy the answer It involves if f (a) =lim or does not or f (a) =f (a)

Answer 1

All elementary functions you learned in high school are continuous in their defined domains. Since f(x) = cos(pi*x/2) is defined everywhere, it is conitinuous everywhere. Or, you can prove that since

lim{y-->x} cos(pi*y/2) = cos(pi*x/2), it is contiunuous everywhere.