Hello everyone
Let's say I want to do this integral:
\int_{}^{}f(x)g(x)\,dx
We use this formula
\int f(x)g'(x)\, dx=f(x)g(x)-\int f'(x)g(x)\, dx
I don't understand the utility of this equation, since we want to find \int_{}^{}f(x)g(x)\,dx and not \int f(x)g'(x)\, dx
Please...