# Delta function integral HELP PLEASE

1. Sep 20, 2008

### mpouternot

1. The problem statement, all variables and given/known data
I want to measure this integral ( Sd(x)δ(χ-c) , where c is constant

2. Relevant equations

3. The attempt at a solution

2. Sep 20, 2008

### HallsofIvy

Staff Emeritus
Do you mean
$\int \delta(x-c)dx$?

What is is the range of integration? Since you use the delta function, I assume you know how it is defined- immediately from the definition that integral is 1 if c is in the range of integration, 0 if not.

If you mean
$$\int_{-\infty}^x \delta(t-c)dt$$
That is the "Heaviside step function" H(x-c), equal to 0 if x< c, 1 if $x\ge c$.