What is the product? Complete the equation.

-5. (-9) =

Use the function nest to evaluate p(x) = 1 + x + · · · + x50 at x = 1.00001. (use the matlab ones command to save typing.) find the error of the computation by comparing with the equivalent expression q(x) = (x51 − 1)/(x − 1).

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) = .

Given the expression (7 ? 4i) ? (2 + 6i), perform the indicated operation and write the answer in the form a + bi.