SOLUTION: What is the equation, in standard form, of a parabola that models the values in the table? x -2 0 4 f(x) -7 3 -73

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: What is the equation, in standard form, of a parabola that models the values in the table? x -2 0 4 f(x) -7 3 -73      Log On


   

Question 622083: What is the equation, in standard form, of a parabola that models the values in the table?
x -2 0 4
f(x) -7 3 -73
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

x	f(x)

-2	-7

0	3

4	-73

 f(x) = ax^2 + bx  + c

 f(0) = ax^2 + bx  + c = 3, c = 3

 f(-2) = 4a + -2b + 3 = -7

 f(4)  =16a + 4b + 3 = -73

 4a  -2b = -10   ||multiplying by 2 and adding to the 2nd EQ to eliminate b

16a + 4b = -76 

      24a = -96

        a = -4   and b = -3   (-16 -2b = -10, -2b = 6, b = -3)

f(x) = -4x^2 - 3x + 3