Find the critical points of the followng equation: (x^3-8)/(x-2)
\[(x^3-8)/(x-2)\]
(Using the quotient rule)
Take the derivative. Critical points are where the function is equal to 0 or DNE. If the top of the fraction equals 0, then the whole thing is equal to 0. If the bottom of the fraction is equal to 0, then it DNE.
Do you know how to use the quotient rule?
Yes, but once I found the derivative, I didn't know where to go. For the derivative I got 2x^3−6x^2+8
Hello?
I believe that you equal that result to zero, then solve for the variables and those should be the critical points. I'm struggling with derivatives myself.
If you do the quotient rule correctly, you will have a fraction
To find critical points, set the top of the fraction equal to 0 and solve, then set the bottom equal to 0 and solve.
I didn't get a fraction though. Here are my steps:\[ f'(x) = \frac{g'(x)h(x) - g(x)h'(x)}{[h(x)]^2} \rightarrow\]
\[((3x^2)(x-2)-(1)(x^3-8))/((x-2)^2)\]
\[\rightarrow (3x^3-6x^2-x^3+8)/(x^2-4x+4)\]
\[\rightarrow 2x^3-6x^2+8\]
Set top equal to 0, solve. Set bottom equal to 0, solve.
would the denominator = 1?
No. There's no reason to simplify that much. Use ((3x2)(x−2)−(1)(x3−8))/((x−2)2).
The original derivative, that is.
Could you help, I'm having trouble solving
hi?
Start with the bottom. X-2=0
For the top, get all of your x terms on one side, and everything else on the other.
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