An 11% fee was
added to $125
credit card
purchase. What
was the total
purchase?

What is the area of triangle abc if a = 8, b = 11, and c = 15?

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) = .

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.