Question

If y = 2x2 - 3x - 10, then x = 0 is a counterexample for which conjecture?

Answer 1

Here's all I can think of:

f(0) = -10.  This is the y-intercept of this parabolic graph.  This point is (0,-10).

If you were to find the inverse of f(x), then (-10,0) would be on the graph.