I want to derive this equation:

$\displaystyle

y*arctan(x-2) + x*arctan(\frac{y-1}{20}) = 0

$

should i first use the product formulae on the terms on each side of the addition sign? Later should I use the sum formulae on that?

Printable View

- Aug 1st 2007, 10:29 AMwizzlerDerive arctangent
I want to derive this equation:

$\displaystyle

y*arctan(x-2) + x*arctan(\frac{y-1}{20}) = 0

$

should i first use the product formulae on the terms on each side of the addition sign? Later should I use the sum formulae on that? - Aug 1st 2007, 10:33 AMKrizalid
You have to use implicit differentiation, the product rule and

$\displaystyle (\arctan{u})'=\frac1{1+u^2}\cdot{u'}$ - Aug 1st 2007, 10:39 AMwizzler
- Aug 1st 2007, 10:47 AMtukeywilliams
- Aug 1st 2007, 10:12 PMearboth
Hello,

I don't want to pick at you ... but I can't see you you around here so I'm going to remove the small typo in your result:

$\displaystyle \frac{y}{1+ (x-2)^2} + \arctan(x-2)y' + \frac{xy'}{20 \left(1+\left(\frac{y-1}{20} \right)^2\right)} + \arctan \left(\frac{y-1}{20} \right) $