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anonymous
 one year ago
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
 one year ago
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

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0before we begin is it clear that two factors are \((x5)\) and \((x+3)\)?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok so the real job (before multiplying out) is the find the quadratic polynoimial with zeros at \(1+2i\) and its conjugate \(12i\)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0you want the easy way, or the real real easy way?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok actually lets to the easy way first then the real real easy way

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0we can work backwards starting with \[x=1+2i\] add 1 and get \[x+1=2i\] then square (carefully) to get \[(x+1)^2=(2i)^2\] or \[x^2+2x+1=4\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0add 4 to both sides and get \[x^2+2x+5=0\] and that is your polynomial

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0the real real easy way requires memorizing something that if \(a+bi\) is a zero of a quadratic, then it is \[x^22ax+(a^2+b^2)\] so in your case \(a=1,b=2\) and the quadratic is \[x^22\times (1)x+(1)^2+2^2\] i.e. \[x^2+2x+5\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0those arent any options tho :(

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0your final job is to multiply \[(x5)(x+3)(x^2+2x+5)\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0if it was me, i would cheat so as not to screw up the algebra when multiplying

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0you know how to do that?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0wait let me try again

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok i will leave you to it, then show you how to get the answer for sure

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0yeah the answer i get does not match up with my choices

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0http://www.wolframalpha.com/input/?i=%28x5%29%28x%2B3%29%28x^2%2B2x%2B5%29

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0see if that one does

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh thankyou! maybe i was multiplying something wrong!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0that is why i said "cheat" is is easy to make a mistake when multiplying all this muck out
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