Hi,(adsbygoogle = window.adsbygoogle || []).push({});

I have to show that if the derivate f'(x) of a generalized function f(x) is defined by the sequence f'_n(x) where f(x) is defined

[tex]f_n(x)[\tex]

then

[tex]\int_{-\infty}^{\infty}f'(x)F(x) dx = - \int_{-\infty}^{\infty}f(x)F'(x) dx [/tex]

I use the limits for generalized functions and get

[tex]lim_{n \to \infty} \int_{-\infty}^{\infty}f'_n(x)F(x) dx = - \int_{-\infty}^{\infty}f_n(x)F'(x) dx [/tex]

which should show the above - I am a liltte confused where the minus sign comes from?

[tex]- \int_{-\infty}^{\infty}f(x)F'(x) dx [/tex]

Any help appreciated - thanks in advance

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Derivate of generalized function

**Physics Forums | Science Articles, Homework Help, Discussion**