The parabolas defined by the equations $y=2x^2-4x+4$ and $y=-x^2-2x+4$ intersect at points $(a,b)$ and $(c,d)$, where $c≥a$. What is $c-a$? Express your answer as a common fraction.
y = 2x^2 - 4x + 4 and y = -x^2 - 2x + 4
First let's find the x values of the intersection points by solving this equation:
2x^2 - 4x + 4 = -x^2 - 2x + 4
Add x^2 to both sides of the equation.
3x^2 - 4x + 4 = -2x + 4
Add 2x to both sides.
3x^2 - 2x + 4 = 4
Subtract 4 from both sides.
3x^2 - 2x = 0
Factor x out of the two terms on the left side.
x(3x - 2) = 0
Set each factor equal to zero.
x = 0 or 3x - 2 = 0
3x = 2
x = 2/3
The x coordinates of the intersection points are 0 and 2/3 .
So c = 2/3 and a = 0
c - a = 2/3 - 0 = 2/3
Here's a graph to check it: https://www.desmos.com/calculator/enndawdskv
y = 2x^2 - 4x + 4 and y = -x^2 - 2x + 4
First let's find the x values of the intersection points by solving this equation:
2x^2 - 4x + 4 = -x^2 - 2x + 4
Add x^2 to both sides of the equation.
3x^2 - 4x + 4 = -2x + 4
Add 2x to both sides.
3x^2 - 2x + 4 = 4
Subtract 4 from both sides.
3x^2 - 2x = 0
Factor x out of the two terms on the left side.
x(3x - 2) = 0
Set each factor equal to zero.
x = 0 or 3x - 2 = 0
3x = 2
x = 2/3
The x coordinates of the intersection points are 0 and 2/3 .
So c = 2/3 and a = 0
c - a = 2/3 - 0 = 2/3
Here's a graph to check it: https://www.desmos.com/calculator/enndawdskv