SOLUTION: a parabola with x=0 as its axis of symmetry has a y-0intercept of 6. One of its x-intercept is 3. Write an equation for the parabola.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: a parabola with x=0 as its axis of symmetry has a y-0intercept of 6. One of its x-intercept is 3. Write an equation for the parabola.       Log On


   

Question 344386: a parabola with x=0 as its axis of symmetry has a y-0intercept of 6. One of its x-intercept is 3. Write an equation for the parabola.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Both zeros must be equidistant from the line of symmetry.
If x=3 is a zero, so is x=-3
f%28x%29=a%28x-3%29%28x%2B3%29
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Use the point (0,6) to find a.
f%280%29=a%280-3%29%280%2B3%29=6
-9a=6
highlight%28a=-2%2F3%29
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f%28x%29=-%282%2F3%29%28x-3%29%28x%2B3%29
highlight_green%28f%28x%29=-%282%2F3%29%28x%5E2-9%29%29
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