Pls answer fast will give brainlest

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

Danielle earns a 7.25% commission on everything she sells at the electronics store where she works. she also earns a base salary of $750 per week. what were her sales last week if her total earnings for the week were $1,076.25?

Find the cosine function that is represented in the graph.