How do you integrate int e^xsinx by parts from [0,1]?

1 Answer
Dec 19, 2016

The answer is =1/2e^x(sinx-cosx)+C

Explanation:

The integration by parts is applied 2 times

intuv'=uv-intu'v

Here,

u=sinx, =>, u'=cosx

v'=e^x, =>, v=e^x

inte^xsinxdx=e^xsinx-inte^xcosxdx

We do the integration by parts a second time

u=cosx,=>,u'=-sinx

v'=e^x,=>,v=e^x

inte^xcosxdx=e^xcosx-inte^x-sinxdx

=e^xcosx+inte^xsinxdx

Therefore,

inte^xsinxdx=e^xsinx-(e^xcosx+inte^xsinxdx)

inte^xsinxdx=e^xsinx-e^xcosx-inte^xsinxdx

So,

2*inte^xsinx=e^x(sinx-cosx)

inte^xsinxdx=1/2e^x(sinx-cosx)+C