The numerator of a certain fraction is three times the denominator. If the numerator is decreased by 1 and the denominator is increased by 2, the value of the resulting fraction is 5/2 . Find the original fraction

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

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) = .

Factor the trinomial below. 12x^2 - 32x - 12 a. 4(3x+3)(x-1) b. 4(3x+1)(x-3) c. 4(3x+6)(x-2) d. 4(3x+2)(x-6)