Question 845157
{{{ R = -4t^3 + 26t }}}
Here's the plot:
{{{ graph( 400, 400, -5, 5, -30, 30, -4x^3 + 26x ) }}}
What are the values of {{{ t }}} for which {{{ R = 0 }}}?
{{{ -4t^3 + 26t = 0 }}}
{{{ t*( -4t^2 + 26 ) = 0 }}}
{{{ t = 0 }}}
and
{{{ -4t^2 + 26 = 0 }}}
{{{ 4t^2 = 26 }}}
{{{ t^2 = 13/2 }}}
{{{ t = 2.55 }}}
The population stops growing ( {{{ R = 0 }}} )
when {{{ t = 2.55 }}} years
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The population growth is positive between
{{{ t = 0 }}} and {{{ t = 2.55 }}} years
Disregard all the negative time on plot