Find the derivative an determine the values

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Suppose f(x) = \frac{(x-3)^{4}}{x^{2}+2x}. Find the derivative an determine the values for which it is equal to 0. So f'(x) = \frac{x^{2}+2x(4(x-3)^{3}) - (x-3)^{4}(2x+2)}{(x^{2}+2x)^{2}}. But now how would I go about finding the values for which the derivative equals 0? f'(x) = \frac{x^{2}+2x(4(x-3)^{3}) (x-3)^{4}(2x+2)}{(x^{2}+2x)^{2}} = 0. Is it possible to factor?

Thanks
 
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For any fraction, let's call it \frac{A}{B}, which part will make the whole thing equal to 0? A or B?
 
A

will yeah
 
plugpoint said:
Suppose f(x) = \frac{(x-3)^{4}}{x^{2}+2x}. Find the derivative an determine the values for which it is equal to 0. So f'(x) = \frac{(x^{2}+2x)(4(x-3)^{3}) - (x-3)^{4}(2x+2)}{(x^{2}+2x)^{2}}. But now how would I go about finding the values for which the derivative equals 0? f'(x) = \frac{x^{2}+2x(4(x-3)^{3}) (x-3)^{4}(2x+2)}{(x^{2}+2x)^{2}} = 0. Is it possible to factor?

Thanks
You missed a set of parentheses.
 
Your derivative isn't correct yet, make sure you check that first!
 
The derivative is correct, assuming that the missing parentheses BobG mentions is put in correctly!
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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