Which number means the same as 7,000,000,000 + 900,000,000 + 20,000,000 + 7,000,000 + 100,000 + 70,000 + 3,000 + 800 + 60? a. 7,927,137,860 b. 7,972,173,860 c. 7,927,173,806 d. 7,927,173,860

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

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) = .

Opposite angles in a parrellelogram are