I need to know how to solve this problem will rep.

Outside temperature over a day can be modeled as a sinusoidal function. Suppose you know the temperature varies between 52 and 68 degrees during the day and the average daily temperature first occurs at 8 AM. How many hours after midnight, to two decimal places, does the temperature first reach 54 degrees?


Thank you!
=]

If it helps I know how to get the first time. but I need the second one to subtract with.