SOLUTION: Find the zeroes of the polynomial f(x) = x^3 + x^2 - 12x.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Find the zeroes of the polynomial f(x) = x^3 + x^2 - 12x.      Log On


   

Question 919927: Find the zeroes of the polynomial f(x) = x^3 + x^2 - 12x.
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29+=+x%5E3+%2B+x%5E2+-+12x

f%28x%29+=+x%28x%5E2+%2B+x+-12%29 .........write x as 4x-3x
f%28x%29+=+x%28x%5E2+%2B4x-3x+-12%29 group
f%28x%29+=+x%28%28x%5E2+%2B4x%29-%283x+%2B12%29%29
f%28x%29+=+x%28x%28x+%2B4%29-3%28x+%2B4%29%29
f%28x%29+=+x%28x%2B4%29%28x-3%29 set f%28x%29+=0}
0=+x%28x%2B4%29%28x-3%29
solutions:
x=0
x%2B4=0=>x=-4
x-3=0=>x=3

+graph%28+600%2C+600%2C+-15%2C+15%2C+-15%2C+25%2C+x%5E3+%2B+x%5E2+-+12x%29+