Question 43622
{{{s = -16t^2 + 240t}}}
{{{416 <= -16t^2 + 240t}}}
{{{104 <= -4t^2 + 60t}}}
{{{26 <= -t^2 + 15t}}}
{{{0 <= -t^2 + 15t - 26}}}
{{{0 <= -t^2 + 2t + 13t - 26}}}
{{{0 <= (-t^2 + 2t) + (13t - 26)}}}
{{{0 <= -t(t - 2) + 13(t - 2)}}}
{{{0 <= (-t + 13)(t - 2)}}}
{{{t = 13}}} and {{{t = 2}}}
Answer: {{{2 <= t <= 13}}}
{{{ graph( 600, 600, -2, 18, -2, 31, -x^2 + 15x - 26 ) }}}