3. Each square has the area written inside and the expression that represents the area is written outside, below the box. Find the side length of each square. 289 in2 1,221 in2 961 in? 36x2 - 12x + 1 - 25x2 – 20x + 4 49x2 - 42x + 9 -

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

Write an algebraic expression to match each statement a. four less than 8 times a number b. twice the difference of a number and six c. nine from a number squared

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) = .