Use identities to find sin2θ and cos2θ, given cosθ= -12/15 and sinθ> 0 plz i need asap giving a lot of points for the one who solves this !

The table below represents a linear function f(x) and the equation represents a function g(x): x f(x) −1 −5 0 −1 1 3 g(x) g(x) = 2x − 7 part a: write a sentence to compare the slope of the two functions and show the steps you used to determine the slope of f(x) and g(x). (6 points) part b: which function has a greater y-intercept? justify your answer. (4 points)