SOLUTION: how do i graph the function 2x^2+8x+4

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Question 287314: how do i graph the function 2x^2+8x+4
Found 2 solutions by Alan3354, texttutoring:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
It's not possible, since it's not a function. It's a polynomial.
If it were y = 2x^2+8x+4 then you could graph it.
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Pick values for x and find y. Plot the points, draw a curve thru them.

Answer by texttutoring(324) About Me  (Show Source):
You can put this solution on YOUR website!
The easiest way (if you don't have a graphing calculator or graphing software) is to turn it from general form (y=ax^2+bx+c) into standard parabola form (y=a(x-p)^2 + q)
You can do this by completing the square:
y=2x%5E2%2B8x%2B4
Factor out the 2 from the x terms:
y=2%28x%5E2%2B4x%29%2B4
Take half of the b=4 term, then square it %284%2F2%29%5E2+=+4, and add it inside the brackets:
y=2%28x%5E2%2B4x%2B4%29%2B4
You added 8 (2 outside the brackets, times the 4 inside) to the equation, so you now have to subtract 8 from the outside:
y=2%28x%5E2%2B4x%2B4%29%2B4-8

Also note that the terms in the brackets now make a perfect square. x%5E2%2B4x%2B4=%28x%2B2%29%5E2

y=2%28x%2B2%29%5E2-4
This is a parabola with a=2, and center at (p,q)=(-2,-4)
If you want to see an image of this graph, or require more explanation, send me a message :)