Angles of polygon find the value of x​

Aregression was run to determine if there is a relationship between hours of tv watched per day (x) and number of situps a person can do (y). the results of the regression were: y=ax+b a=-0.662 b=30.418 r2=0.703921 r=-0.839

For which pair of functions is (gof)(a)=|a|-2?

Which of the following is the result of expanding the series