Posted by bowershe on .
What is the equation, in standard form, of a parabola that models the values in the table?
x –2 0 4
ƒ(x) 1 5 59

algebra 
Sam,
ax^2 + bx + c = 1
plug in first value
4a 2b + c = 1
do the same for the others:
0 + 0 + c = 5
c = 5
16a + 4b + c = 59
so we plug in c into the equations with and b:
16a + 4b + 5 = 59
4a 2b + 5 = 1
4a = 2b 4
2a = b  2
16a + 4b = 64
8(b2) + 4b = 64
2(b2) + b = 16
2b  4 + b = 16
3b = 12
b = 4
Plug in for a
2a = 4  2
2a = 6
a = 3
So the equation is:
3x^2  4x + 5