1. Prove that

2 tan x / 2- sec^2 x = tan 2x.

Aplane intersects a pris paralel to the base of the prism. the cross section is a polygon wth eight sides. how many sides does the base of the prism have? a. 10 b. 8 c. 7 d. 9

What are the solutions for the following system? -2x^2+y=-5 y=-3x^2+5

Robert is placing sod in two square shaped areas of his backyard. one side of the first area is 7.5 feet. one side of the other area is 5.7 feet. the sod costs y dollars per square foot