How do you find the antiderivative of #e^(-2x)#?
it is important to remember that
so let us see what happens if we differentiate the given function
by the chain rule we have:
now integration is the reverse of differentiation, so comparing what we have after differentiating and the function we are given to integrate.
we have to adjust the function by a suitable constant to cancel the
if you now differentiate the resulting function you will see it gives the original function.