From a bag containing 2 red marbles and 1 white marble, eight times Eliana randomly picked a marble. All eight times she picked a red marble. If she picks a marble from the bag again, what is the probability that she'll pick a white one?​

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) = .

Me n o w. i need t h i s. 10 points

Proving the parallelogram diagonal theoremgiven abcd is a parralelogam, diagnals ac and bd intersect at eprove ae is conruent to ce and be is congruent to de