Question

Graph 2x^3 + 9x^2 + 4x - 15 = 0

Answer 1

You mean graph y = 2x^3 + 9x^2 + 4x - 15

I suspect
http://www.wolframalpha.com/widgets/view.jsp?id=eddad051a15adadc20c85a7b1b455fa1