Which of the following equations represent the graph above?
- y = 2+7x+4x2
- y = 2-7x+4x2
- y = 2+7x-4x2
-
y = 2-7x-4x2
The correct answer is: D
Explanation
x = -2 and x = 1/4
x = -2 and 4x = 1
x+2 and 4x-1
(x+2)(4x-1) = 0
4x2 - x + 8x -2 = 0
4x2 + 7x – 2 = 0 but y intercept is positive. Multiply the equation by -1
-4x2 - 7x + 2 = 0
∴y = 2 – 7x – 4x2
There is an explanation video available .