I=int_0^(π/2)e^xsinxdx
We will use integration by parts
int_0^(π/2)e^xsinxdx=int_0^(π/2)(e^x)'sinxdx =
[e^xsinx]_0^(π/2) - int_0^(π/2)e^x(sinx)'dx
[e^xsinx]_0^(π/2) - int_0^(π/2)e^xcosxdx
[e^xsinx]_0^(π/2) - int_0^(π/2)(e^x)'cosxdx
[e^xsinx]_0^(π/2) - [e^xcosx]_0^(π/2)+int_0^(π/2)e^x(-sinx)dx
[e^xsinx]_0^(π/2) - [e^xcosx]_0^(π/2)-int_0^(π/2)e^xsinxdx
If int_0^(π/2)e^xsinxdx=J
then
I+J=2int_0^(π/2)e^xsinxdx
2int_0^(π/2)e^xsinxdx=[e^xsinx]_0^(π/2) - [e^xcosx]_0^(π/2)
int_0^(π/2)e^xsinxdx=([e^xsinx]_0^(π/2) - [e^xcosx]_0^(π/2))/2
int_0^(π/2)e^xsinxdx=(e^(π/2)sin(π/2)-e^0sin0 - e^(π/2)cos(π/2)+e^0cos0)/2
int_0^(π/2)e^xsinxdx=(e^(π/2)+1)/2