Naked Science Forum
General Science => General Science => Topic started by: malylo on 10/11/2011 03:01:47

Look at the function: f(x)=9x^2+12x+4. Please find xintercept and yintercept.
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y=9x^{2}+12x+4
The Yintercept is easy to calculate. Just set X=0.
y=9*0^{2}+12*0+4 = 4
To calculate the Xintercept, it is easiest to first factor the quadratic, in this case it is relatively easy, a perfect square.
y=(3x+2)(3x+2)
Now, set Y=0.
0=(3x+2)(3x+2)
So, either half (which is the same) must equal zero.
0=3x+2
3x=2
x=2/3