If you randomly selected 10 people out of 100 to help you pass out food, how would you find the number of different combinations?
1.Counting Principle
2.Permutaion
3.Combination

Given the following statements, which is the best

The parabola opens: y=√x-4 (principal square root) up down right 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) = .