SOLUTION: If y=-2x^6-32x^3-118, does y have a maximum or a minimum value? What is the value? What is the corresponding value of x?

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: If y=-2x^6-32x^3-118, does y have a maximum or a minimum value? What is the value? What is the corresponding value of x?      Log On


   

Question 982223: If y=-2x^6-32x^3-118, does y have a maximum or a minimum value? What is the value? What is the corresponding value of x?
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Best handled using derivatives.

dy%2Fdx=-12x%5E5-32%2A3x%5E2
-12x%5E2%28x%5E3%2B8%29

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.