Question

Help please!

The points (0,-14), (1,-3), (2,0), (3,5) are on a parabola. Write the function to represent this parabola.

Answer 1

y= -4x^2 + 15x - 14

Explanation:

Answer 2

y= -4x^2 + 15x - 14

Explanation:

A parabola is always in the form y = ax^2 + bx + c.

Substitute each point to produce different equations:

-14 = 0a + 0b + c = c

so c = -14

-3 = a1^2 + b1 + c = a + b - 14

so a + b = 11

0 = a2^2 + b2 + c = 4a + 2b -14 = 0

so 4a + 2b = 14

if we double a + b = 11 we get 2a + 2b = 22

Subtract this from 4a + 2b = 14 and we get 2a = -8 so a= -4 and b = 11 - a = 15

We don't need to use the (3,5) points as we have all the information we need.