Question

If y=-x^2+14x+7 then x=10 is a counterexample for which conjecture?

A.

y is always positive.
B.

y is always negative.
C.

y is a function of x.
D.

The graph of y is a parabola.

Answer 1

Substitute x = 10 into the equation and see if it is positive, negative, or zero. This information will answer the question.

Answer 2

thank you so much

Answer 3

What did you decide?

Answer 4

positive

Answer 5

Okay, so evaluating the right-hand side at x = 10 produces a positive result. Now answer the question.