Marcy buys a box containing 5 pizzas at the supermarket. the box of pizzas costs $24.25 and marcy is charged an additional $1.21 in tax. she figures, with the tax, she paid $8.47 for each pizza. estimate the cost of each pizza. is marcy's calculation reasonable?

What term best describes a line and a point that lie in the same plane? a. congruent b. coplanar c. collinear d. equal

Celeste wants to have her hair cut and permed and also go to lunch. she knows she will need $50. the perm cost twice as much as her haircut and she needs $5 for lunch. how much does the perm cost?

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) = .