I am having trouble understanding how you take the convolution of two functions.
For example, if $f_1(x) = x$, with x ranging from [0,X] how do I solve for $f_2(x)$ when $$f_2(x) = \int_{0}^{\infty} f_1(x')f_1(x-x') dx'.$$ Do I need to use an indicator function?
Thanks
in your example you sustitute $f_1(x')=x'$ and $f_1(x-x')=x-x'$ in an analagous way and solve the integral having the $x'$ as your integral's variable.
If the integral converges, you will get a result in terms of x and it will be the convolution of $f_1$ with itself. if the integral dows not converge, you can't make the convolution.