I'm having trouble with differentials. I've been trying to learn about them online using great resources like PatrickJMT but I'm having trouble finding examples for this kind or problem. I hate asking questions when I don't have any work to show but I'd like some help to get started.
Find the differential of the following function:$$y = \frac{u+1}{u-1}$$
If someone could show me how to begin or link me to some information on the web, that would be great!
$\endgroup$2 Answers
$\begingroup$$$\frac{dy}{du}=\frac{d}{du} \left ( \frac{u+1}{u-1}\right )=\frac{u-1-u-1}{(u-1)^2}=\frac{-2}{(u-1)^2}$$
$$dy=\frac{-2}{(u-1)^2} du$$
$\endgroup$ 2 $\begingroup$Depends on your knowledge of differentials and derivatives. In most of the cases, you are taught about differentials via derivatives, and for functions of one variable you always get $$ dy(u) = y'(u)du. $$ So you only have to compute the derivative $y'(u)$ e.g. via the derivative rule for fractions, and put $du$ from the right of that.
$\endgroup$ 3
