<PRE><B>Question 89510</B>
1.  the axis of symmetry for a graph of the form ax^2+bx+c is x=-b/2a ... since b=0 in this case, the axis of symmetry is x=0 (the y-axis)


2.  the arch touches the ground when h(x)=0 ... 0=-5x^2/64+4 ... -4=-5x^2/64 ... -256=-5x^2 ... 51.2=x^2 ... x=+-7.16 (approx.)


3.  the maximum height occurs at the axis of symmetry, where x=0 ... h=-5(0)^2/64+4 ... h=4


4.  a thru g ... to find the height of the posts, plug the distance (x) values into the function and evaluate</PRE>