Use the distributive property to simplify 5(2x+3). 7x + 3

7x + 8

10x + 15

10x + 25

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

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .