Highway engineers design a parabolic curve for an entrance ramp from a straight street to an interstate highway. The vertex of the curve passes through (0, 0) and the parabola passes through (1000, + 800). Find an equation for the parabola.

Question

anonymous · Answer

two situation:
1.the curve opens up. 
|dw:1338005686179:dw|
so the equation is $$ay=x ^{2}$$
we substituted (1000,800) into the equation and find that a=0.04
so it is$$0.04y=x ^{2}$$
2. the curve opens right
|dw:1338005953151:dw|
so the equation is $$y ^{2}=ax$$
we substituted (1000,800) into the equation and find that a=0.03
so it is$$y ^{2}=0.03x$$