SOLUTION: A cubic polynomial equation, P(x)=0, has real coefficients and a leading coefficient of 1. One of its roots if 1+2i and the sum of the roots is 14. Write P(x) in polynomial form.

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: A cubic polynomial equation, P(x)=0, has real coefficients and a leading coefficient of 1. One of its roots if 1+2i and the sum of the roots is 14. Write P(x) in polynomial form.      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1104658: A cubic polynomial equation, P(x)=0, has real coefficients and a leading coefficient of 1. One of its roots if 1+2i and the sum of the roots is 14. Write P(x) in polynomial form.
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Two roots are 1-2i and r, and the given root is 1+2i.

If sum of these roots is 14 then %281%2B2i%29%2B%281-2i%29%2Br=14;
r=12.

P%28x%29=%28x-%281%2B2i%29%29%28x-%281-2i%29%29%28x-12%29
Do the simplification.
.
.
highlight%28x%5E3-14x%5E2%2B29x-60%29