If the vertex is at (0,0), you know that when x=±15/2, y=12
so, if y = kx^2
12 = k(15/2)^2, so
k = 12*4/225 = 48/225 = 16/75
y = 16/75 x^2
Now, if you don't want to consider negative values for x, then it would make sense to translate the vertex to (7.5,0), so you are correct.
A new skateboarder's ramp just arrived at Bungey's Family Fun Center. A cross -sectional view shows that the shape is parabolic. The sides are 12 ft high and 15 ft apart. Write an equation that, when graphed, will show the cross section of this ramp.
Is this correct? y=16/75(x-7.5)^2
1 answer