SOLUTION: PLEASE HELP!!!! Given the polynomial function f(x)=x^3-5x^2+11x-15; 3 is a given zero, find the other zeros.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: PLEASE HELP!!!! Given the polynomial function f(x)=x^3-5x^2+11x-15; 3 is a given zero, find the other zeros.      Log On


   

Question 941336: PLEASE HELP!!!! Given the polynomial function f(x)=x^3-5x^2+11x-15; 3 is a given zero, find the other zeros.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Perform synthetic division to find the quadratic, possibly factorable, factor.

3________________|______1______-5______11_______-15
_________________|
_________________|_____________3_______-6________15_________
_______________________1______-2_______5_________0

The remainder there is 0.
The quotient means, x%5E2-2x%2B5 and not factorable.


Those roots are %282%2B-+sqrt%284-4%2A5%29%29%2F2
%282%2B-+2%2Asqrt%28-4%29%29%2F2
%282%2B-+4%2Ai%29%2F2
highlight%281%2B-+2i%29. These are the two other zeros.