I have one last question for the parabolic arch.
If a parabolic arch satisfies the equation y=16 - 0.25x^2 for y>0.
How would I find the width [I]w/I] of the arch?
lets assume that the ground level corresponds to y=0, then is we
solve 16-0.24 y^2=0, we will find the two points that the arch touches
ground and the width will be the difference between them, so:
16-0.24y^2=0,
or:
0.25 y^2=16
taking square roots:
(1/2) y= +/- 4
y=-8 or +8.
So the width of the arch is 8-(-8)=16.
RonL