inte^x[((sin^-1x)sqrt(1-x^2)+1)/sqrt(1-x^2)]dxex[(sin1x)1x2+11x2]dx ?

2 Answers
Jul 28, 2016

e^x(sin^-1x)+Cex(sin1x)+C

Explanation:

We have:

inte^x[((sin^-1x)sqrt(1-x^2)+1)/sqrt(1-x^2)]dxex[(sin1x)1x2+11x2]dx

Splitting up the fraction, this becomes:

=inte^x[sin^-1x+1/sqrt(1-x^2)]dx=ex[sin1x+11x2]dx

Split up the integrals:

=inte^x(sin^-1x)dx+inte^x/sqrt(1-x^2)dx=ex(sin1x)dx+ex1x2dx

Attempt to integrate inte^x(sin^-1x)dxex(sin1x)dx via integration by parts, which takes the form intuv=uv-intvduuv=uvvdu.

Let u=sin^-1xu=sin1x, so du=1/sqrt(1-x^2)dxdu=11x2dx, and dv=e^xdxdv=exdx, so v=e^xv=ex.

Thus we see that the original integral equals:

=[e^x(sin^-1x)-inte^x/sqrt(1-x^2)dx]+inte^x/sqrt(1-x^2)dx=[ex(sin1x)ex1x2dx]+ex1x2dx

The integral inte^x/sqrt(1-x^2)dxex1x2dx will cancel with itself, leaving just

=e^x(sin^-1x)=ex(sin1x)

Add the constant of integration:

=e^x(sin^-1x)+C=ex(sin1x)+C

Jul 28, 2016

e^x(sin^-1x)+Cex(sin1x)+C

Explanation:

There is a pattern surrounding integrals involving e^xex, in cases like this problem (and all the others surrounding it on the page).

Since:

d/dxe^xf(x)=e^xf(x)+e^xf'(x)=e^x[f(x)+f'(x)]

Then:

inte^x[f(x)+f'(x)]dx=e^xf(x)+C

This is the case for the given problem, which simplifies to be:

inte^x[sin^-1x+1/sqrt(1-x^2)]dx

If f(x)=sin^-1x, then f'(x)=1/sqrt(1-x^2).

Thus the integral equals

=e^xf(x)+C=e^x(sin^-1x)+C