Hi. I was taking a practice test for a Math Contest and I can not figure out what the answer to one question is. Here is the question:

The function has roots (i.e. ). Find .

A. 7

B. -7

C. 0

D. -5

E. None of these.

Correct answer: B

I used the zeros function on the TI 89, and it said that the only zero of the function was -8.65..., so I put E, but I don't see why this is wrong. Could someone explain this question to me? Thanks!