Question

Find the complex zeros of the polynomial function. Write f in factored form. f(x)=x^3-9x^2+28x-30

Answer 1

Do you know how to start this?

Answer 2

I am stuck actually.

Answer 3

How much work have you done?

Answer 4

Did you use the quadratic formula?

Answer 5

If I were to solve this, I would first factor, and then solve the remaining part by using the quadratic formula.

Answer 6

So, the factored form looks like:

Answer 7

(x-3)(x^2-6x+10)=0

Answer 8

Do you follow so far?

Answer 9

yes I got that part

Answer 10

okay, now solve each part
(x-3)=0
(x^2-6x+10)=0.....solve this using the quadratic formula. You'll get two imaginary roots.

Answer 11

Or you can solve: (x^2-6x+10)=0..... by completing the square.

Answer 12

okay so that part is x=6+2i/2, x=6-2i/2

Answer 13

Yes, you can also further simplify those imaginary roots and get: x=3+i and x=3-i

Answer 14

So you have x=3, x=3-i, x=3+1

Answer 15

That pretty much means that there is a triple root at x=3

Answer 16

so x=3 is what it should be written as or x=3, x=3-i, x=3+1

Answer 17

It should be written as x=3, 3+/-i...... +/- means plus over minus.

Answer 18

ok I see, thanks.