SOLUTION: polynomial graphing f(x) = 2x^3-x^2-8x+4 Please help

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Question 22476: polynomial graphing
f(x) = 2x^3-x^2-8x+4

Please help
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29+=+2x%5E3-x%5E2-8x%2B4

Begin by factoring by grouping:
f%28x%29+=+x%5E2%282x-1%29+-4%282x-1%29

Take out the common factor of (2x-1):
f%28x%29+=+%282x-1%29%28x%5E2+-+4%29+

Factor the difference of squares:
f%28x%29+=+%282x-1%29%28x-2%29%28x%2B2%29+

The roots (or zeros, or x-intercepts) of this function are at
x=1/2, x= 2, x=-2.

Because the highest power of x in this function is to the third power (the degree of the polynomial is odd), this graph will open up on the right side, and down on the left side.

Using a graphing calculator, it looks like this:
graph+%28300%2C600%2C-5%2C5%2C-10%2C10%2C++2x%5E3-x%5E2-8x%2B4%29

R^2 at SCC