Pls answer this exponents and powers question

Find the average rate of change for f(x) = x2 − 3x − 10 from x = −5 to x = 10.

Evaluate cos2θ for cosθ = square root of 3/2

Boris needs to buy plastic spoons. brand a has a box 42 spoons for $2.37. brand b has a box of 72 spoons for $3.57. find the unit price for each brand. then state which brand is the better buy based on the unit price. round your answer to the nearest cent.