5. 6.
How many feet from the base of a house must a
39-foot ladder be placed so that the top of the
ladder will reach a point on the house 36 feet from
the ground?

If sr is 4.5cm and tr is 3cm, what is the measure in degrees of angle s?

Given: pqrs is a parallelogram prove: pr and qs bisect each other at t

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) = .