# Dirac delta function

athrun200

## The Attempt at a Solution

Can I write, say, $f(x) \delta(x)=f(2)\delta(x)$?
Since $\delta(x)$ =0 for x$\neq$0

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## Answers and Replies

Homework Helper
I think you can say $f(x)\delta (x-2)=f(2)\delta (x)$

athrun200
I think you can say $f(x)\delta (x-2)=f(2)\delta (x)$

Then if x=2, left hand side will become infinity and the right hand side 0.
Is it Ok?

athrun200
So what's wrong with my post in #1?

Science Advisor
Homework Helper
So what's wrong with my post in #1?

The integral of $f(x) \delta(x)$ over x is f(0). The integral of $f(2) \delta(x)$ over x is f(2). So no, they aren't the same.