Determine the zero's
f(x) = kx^3 - 8x -x +3k + 1 k=3 and has a zero when x = 2
3x^3 - 8x^2 - x + 3(3) + 1
= 3x^3 - 8x^2 - x +10 <<<<< don't know what to do after this step
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Originally Posted by Devi09 ... It's hard to follow what you did: what happened to k?
Well you had to first find the value of k which is 3 after you solve for it given one of the zeros which was 2
You probably have to factor 3x^3 - 8x^2 - x +10 to get the zeros. But Im stuck at that part
Originally Posted by Devi09 You probably have to factor 3x^3 - 8x^2 - x +10 to get the zeros. But Im stuck at that part You know that x=2 is a root, so (x-2) is a factor. So divide 3x^3 - 8x^2 - x +10 by (x-2) to get the quadratic which will give you the two remaining roots.
Hello, Devi09! . . Why do they do that? . . . Can't they plug in the 3? . .
So we have: .
Since , then is a factor of
We find that: .
Therefore, the zeros are: .
Edit: Too slow . . . again.
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