Question

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Write a polynomial function of minimum degree with real coefficients whose zeros include those listed. Write the polynomial in standard form.
4, -2, and -1 + 2i

Answer 1

@Hero if you would like to help.

Answer 2

Is this a question you've answered already?

Answer 3

I have, but im not sure im right, i get confused in some of the steps sometimes

Answer 4

Okay, so what answer did you get for this?

Answer 5

f(x) = x4 - 3x3 + 8x2 + 13x + 40

Answer 6

So here's what you're supposed to do for these:

They give you the zeroes so you do this:

x = -2
Then add 2 to both sides:
x + 2 = 0


x = 4

Subtract 4 from both sides
x - 4 = 0



x = -1 - 2i
x = -1 + 2i

then add the terms on the left to the other side to get

x + 1 + 2i = 0
x + 1 - 2i = 0

Then you take all the terms that have been set equal to zero, and multiply them

(x + 2)(x - 4)(x + 1 + 2i)(x + 1 - 2i)

After doing so, you get:

\(x^4-7 x^2-26 x-40\)

Answer 7

I did some multiplying wrong...

Answer 8

Are you sure you multiplied the right factors?

Answer 9

Thank you though, i see what i did wrong. Every question i post, i have multiply that are the same with different numbers so after i understand it i go and do the other ones on my own.