My cousin with geometry and i don't remember how to do it. ! these are some of the questions on the assignment

Me i’m stuck on all these questions besides the two bottom ones

What is the maximum of the sinusoidal function

Aresearcher believes increased perceived control influence the well-being of residents at a nursing home. to test this , she allowed one group of residents to have control over their daily lies, (where to eat etc) . the other group of 5 residents had these deceisions made by staff. the resident's feelings of well-being were measured on a 10 point scale at the end of a one month trial period. is there a difference on well-being?