Asked by opo

h(t)=48-40cos(πt/45)
When does the rider first reach a height of 17 feet? Give your answer to the nearest second.
Answered by oobleck
that would be when
48-40cos(πt/45) = 17
40cos(πt/45) = 31
cos(πt/45) = 31/40
now, just find arccos(31/40) and you're almost done.