Use the quadratic formula to solve x² + 8x + 9 = 0. what are the solutions to the equation? round irrational solutions to the nearest tenth.
x=−1.2 and x=−6.8
x = 1 and x=−9
x=−6.6 and x=−1.4
x=−1 and x=−8

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) = .

There are three grizzly bears in the city zoo. yogi weighs 400.5 pounds, winnie weighs 560.35 pounds, and nyla weighs 628.29 pounds. what is the average weight of the three bears? (hint: what do they weigh all together? ) a. 502.97 pounds c. 604.38 pounds b. 529.71 pounds d. 794.57 pounds

Which polynomial is in standard form? 3xy+6x®y2 - 4x4y + 19x? y* 18x5 - 7x{y-2xy2 + 1774 x5y5 - 3xy - 11x? y2 +12 15+ 12xy2 - 11x®ys +5x? y2 ?