Go on the link for a meme

Asap! i'm not good math and i'm lost.

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

Michael gose to a theme park and rides two different roller coasters that both begin on a raised platform his height while on the first roller coaster measured in feet from the platform height can be modeled by the following graph where t is the number of seconds since the ride began