Posted by Tom on .
evaluate the limit:
lim cos(x + pi/2)/x
x>0

Calculus 
Reiny,
cos(x+pi/2)
= cosx cos pi/2  sinx sin pi/2
= 0  sinx
= sinx
so
limit cos(x+pi/2)/x as x> o
= lim sinx/x , x > 0
= 1
using the fact that lim sinx/x = 1