Question 982223
Best handled using derivatives.


{{{dy/dx=-12x^5-32*3x^2}}}
{{{-12x^2(x^3+8)}}}


Where is this expression, a rate of change for y with x, zero?  That would be where original equation y is either flat horizontally, OR a maximum or a minimum.


You will find that the value for x at which the first derivative is zero is x=-2.
Just plug in NEGATIVE 2, in the sixth-degree equation, and find out this maximum value.