Gosh, I feel so darn stupid.....

All i have different is the numbres. I've plugged them in the problems u helpped me with and still cannot get them right...

"For the quadraic function f(x) = 5.71x^2 -3.135x -5.64, find the maximum or minimum value, the x-intercepts, and the y-intercept."

I guess I'm going to spend hours on end heere trtying to understand it. I have 4 HW assignments and 3-4 tests due next week. I need help despirately