Which statements must be true? Check all that apply. A'A = C'C

C'Q = QC

Line P T⊥ A'A

C'C ⊥ B'B

A'A || B'B

m∠TRB = 90°

With these: 18/36 = 1/? missing number change 1 5/8 to improper fraction. change 19/5 to a mixed number.

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

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) = .