Please Help!!

Write a polynomial function of minimum degree with real coefficients whose zeros include those listed. Write the polynomial in standard form.

5, -3, and -1 + 2i

Question

Please Help!!

Write a polynomial function of minimum degree with real coefficients whose zeros include those listed. Write the polynomial in standard form.

5, -3, and -1 + 2i

anonymous · Answer

one part will look like $$(x-5)(x+3)$$

anonymous · Answer

there are a few ways to find a quadratic with zeros $-1+2i$ and $-1-2i$
one way is to work backwards

anonymous · Answer

put $$x=-1+2i$$ add 1$$x+1=2i$$ square both sides  (carefully)$$(x+1)^2=(2i)^2\x^2+2x+1=-4$$ add 4 
$$x^2+2x+5$$

anonymous · Answer

your answer will be what you get when you multiply 
$$(x-5)(x+3)(x^2+2x+5)$$

anonymous · Answer

ok thank you!!!!

anonymous · Answer

yw btw i would cheat for the last part http://www.wolframalpha.com/input/?i=%28x-5%29%28x%2B3%29%28x^2%2B2x%2B5%29

anonymous · Answer

haha thats exactly what i did XD