Question 89399
1.  the function has no x term (as opposed to x^2) so the axis of symmetry is the y-axis


2.  the arch touches the ground when h=0, so 0=-5x^2/64+4 ... -4=-5x^2/64 ... -256=-5x^2 ... 51.2=x^2 ... x=+-7.16 (approx.)