SOLUTION: I am asked to create a quadratic function, y=f(x), that satisfies the following conditions: f(7)=2, f(-5)=-10, and y-intercept is (0,6) NO clue where to begin. I know I could

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: I am asked to create a quadratic function, y=f(x), that satisfies the following conditions: f(7)=2, f(-5)=-10, and y-intercept is (0,6) NO clue where to begin. I know I could      Log On


   



Question 426420: I am asked to create a quadratic function, y=f(x), that satisfies the following conditions:
f(7)=2, f(-5)=-10, and y-intercept is (0,6)
NO clue where to begin. I know I could do something if I had the x-intercepts. But what I start with is:
6=ax^2+bx+c , but then I come up with 6=c and I feel like I just need a starting point.
I was not tought this in my current class, supposedly this is suppose to be prerequisite homework...
Thanks for any help...Kate

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
f(x) = ax^2 + bx + c
Find a, b & c is the problem.
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c = 6, the y-intercept, because
f(0) = 6
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f(7) = 49a + 7b + 6 = 2
f(-5) = 25a - 5b + 6 = -10
Now it's 2 eqns with 2 variables, a & b.
Can you finish it?
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I get f(x) = -11x^2/35 + 57x/35 + 6