can someone solve
∫9xcos(3x+1)dx
Hello,
Define the functions $\displaystyle f(x)=9x$ and $\displaystyle g(x)=\cos(3x-1)$.
Choose which function you would like to integrate and which one you would like to diferentiate. Then simply apply the formula:
$\displaystyle \int f(x)g(x)= F(x)g(x)-\int F(x)g'(x)$
Hello,
The functions I defined were not meant to be fixed. You could just swop them around. I just wanted the basic idea to be understood, i.e. that you may choose either one of the function to integrate or differentiate, ofcourse selecting wisely.