Element X decays radioactively with a half life of 7 minutes. If there are 120 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 2 grams?

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) = .

Which equation has a constant of proportionality equal to 9

What is the method used to multiply binomials using foil?