Question

A student draws two parabolas on graph paper. Both parabolas cross the x-axis at (-4, 0) and (6, 0). The y-intercept

of the first parabola is (0, -12). The y-intercept of the second parabola is (0, -24). What is the positive difference
between the a values for the two functions that describe the parabolas? Write your answer as a decimal rounded to
the nearest tenth.

Answer 1

1/2

Explanation:

First parabola f(x1) = a ( x+4)(x-6) use point 0,-12 to find a = 1/2

= 1/2 (x+4)(x-6)

Second parabola a ( x+4) (x-6) using point 0, -24 shows a = 1

f(x2) = (1)(x+4)(x-6)

Difference between the 'a' values = 1 - 1/2 = 1/2