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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: Water on March 01, 2011, 09:19:12 pm

Title: Quotient Differentiation-Quotient Rule
Post by: Water on March 01, 2011, 09:19:12 pm: Hey guys

I need to find the f'(x) of x/ Square Root (x+1)

So, basically, I can do all the steps, till it hits the last step, in which i can't get the final answer. And its annoying me, perhaps someone can care to enlighten me. I"m sure, I"m going to kick myself after someone simplifies it for me LOL.

I get to my final answer: (x+1)^1/2 - 1/2 x(x+1)^-1/2 divided by x+1

After that, =(, my answer side tracks from calculator T_T
Title: Re: Quotient Differentiation-Quotient Rule
Post by: xZero on March 01, 2011, 09:44:27 pm: $f(x)=\frac{x}{\sqrt{x+1}}$

$f'(x)=\frac{\sqrt{x+1}-\frac{x}{2\sqrt{x+1}}}{x+1}$

$f'(x)=\frac{2x+2-x}{2\sqrt{x+1}}\times\frac{1}{x+1}$

$f'(x)=\frac{x+2}{2(x+1)^{\frac{3}{2}}}$
Title: Re: Quotient Differentiation-Quotient Rule
Post by: Water on March 01, 2011, 09:47:07 pm: Ahh, I see see, you legend :) *palm face* :2funny: