How do you find all the zeros of f(x)=x3+6x26x36?

1 Answer
Mar 5, 2016

Factor f(x) to see that the zeroes occur at 6, 6, and 6

Explanation:

Using the technique of factoring by grouping as well as the difference of squares formula , we can factor f(x) as

x3+6x26x36=x2(x+6)6(x+6)

=(x26)(x+6)

=(x+6)(x6)(x+6)

In its factored form, we can see that the zeros occur when any of the factors become 0, that is, when x=6 or x=±6.