STEP 1
[tex]\begin{gathered} y=-16x^2+63x+4 \\ \frac{dy}{dx}=-32x+63 \\ \\ At\text{ the maximum point }\frac{dy}{dx}=0 \\ \text{Hence} \\ 0=-32x+63 \\ 32x=63 \\ x=\frac{63}{32}=1.969 \\ \text{Step 2} \\ \text{substitute for x in the equation} \\ y=-16(1.969)^2+63(1.969)+4 \\ y_{\max }\approx66.02\text{ ft} \end{gathered}[/tex]Since the maximum value of y is less than 68 ft, the height of the tree, then the arrow can not pass over the tree
