Question

Find the smallest real zero for
f(x) = x^3 + 7x^2 + 4x + 28

Answer 1

First you need to find all the zeros, if you're going to compare them and choose the smallest real zero. Have you considered how you'd find the zeros of f(x) = x^3 + 7x^2 + 4x + 28?
I'd use synthetic division myself, but there are other ways as well.

Hint: What are some of the integer factors of 28, whether positive or negative?

Answer 2

the zeroes are 2i,-2i, and -7

Answer 3

Let's verify that -7 is a zero:

-7 | 1 7 4 28
-7 0 -28
----------------------
1 0 4 0

since there is no remainder, yes, -7 is a root.

You say that the three zeros are -7, 2i, and -2i

From these three zeros, please choose the smallest real zero.

Answer 4

-7?

Answer 5

Right. That's the only real zero, so is the only possible answer.

Answer 6

thank you