SOLUTION: Find the zeros of the polynomial function: P(x) = (x2 + 9)(x + 3)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Find the zeros of the polynomial function: P(x) = (x2 + 9)(x + 3)      Log On


   

Question 458644: Find the zeros of the polynomial function: P(x) = (x2 + 9)(x + 3)
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
P%28x%29+=+%28x%5E2+%2B+9%29%28x+%2B+3%29
P%28x%29+=+%28x%5E2+%2B+3%5E2%29%28x+%2B+3%29..........
we can factor x%5E2%2B3%5E2 like this:
...substitute
P%28x%29+=+%28x-3i%29+%28x%2B3i%29%28x+%2B+3%29
so, solutions are:
x-3i=0....->..... x=3i
x%2B3i=0....->..... x=-3i
x%2B3=0....->..... x=-3
here is a graph for P%28x%29+=+%28x%5E2+%2B+9%29%28x+%2B+3%29=x%5E3%2B3x%5E2%2B9x%2B27:
+graph%28+500%2C+500%2C+-50%2C+60%2C+-50%2C+60%2C+x%5E3%2B3x%5E2%2B9x%2B27%29+