I saw the following equations.

$$ \begin{align} \delta(ax) &= \frac {1} {\lvert a \rvert} \delta(x)\\ \delta(x^2-a^2) &= \frac {1} {2\lvert a \rvert} \left [ {\delta(x+a) + \delta(x-a)} \right ] \end{align}$$

I think the equation below is the general expression. Can someone let me know how the equation below is induced?

$$ \delta \left [ g(x) \right ]=\sum_i \frac { \delta(x-x_i) } { g'(x_i) } $$

Please don't use slang and abbreviations. I am not a native English speaker.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.