lim (cos(π/4 + h) - cos (π/4))

Question

h->0 _________________________
h

Somehow I ended up with cos(1).

Answer 1

lim (cos(π/4 + h) - cos (π/4)) / h
h->0

Answer 2

A store bought a toy rocket at a cost of $40 and marked it up 25%. Ronnie bought it and paid 10% sales tax. What was his total cost?