Question 134062
What is the value of h at the base? that's right 0.

So you need to find the two places where the function yileds a 0 result

Given: {{{h = -0.043d^2 + 2.365d }}}
{{{h = d(-0.043d + 2.365) }}}
{{{0 = d(-0.043d + 2.365) }}}

This equation is zero when either term on the right is 0
That yields d=0 and (-0.043d + 2.365)=0
{{{(-0.043d + 2.365)=0}}}
{{{ -0.043d = -2.365}}}
{{{ d = 55 }}}
So the base is 55 metres wide.