Your long distance telephone provider offers two plans plan a has a monthly fee of $15 and $0.25 per minute plan b has a monthly fee of $20.05 per minute write and solve an equation to find the number of minutes that you must talk to have the same cost for each plans

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) = .

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0

Eden has a part time job. she is paid ? 7.20 an hour the week she worked 18 and a half hours how much is she paid