Pleas help me and no links pictures are okay im giving 100pts and brainleast

Suppose a ball is dropped fromca height of 6ft. it bounces back up but time it bounces, it reaches only 7/10 of its pervious height. what is the total of each height that the ball reaches after 5 bounces

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).