Integration by Parts: Solving Homework

[crm08]

Homework Statement

\int(sin(x)^{-1}), dx

Homework Equations

*By Parts Formula: f(x)g(x) - \int(g(x) f'(x)) dx

Also for d/dx sin(x)^{-1} I used 1/sqrt(1-x^{2})

The Attempt at a Solution

Just started learning this method, I tried letting f(x) = sin(x)^{-1} and g(x) = dx but nothing really simplified, can someone help with selecting the correct g(x) and f(x), Thanks

 

[cristo]

Homework Statement

\int(sin(x)^{-1}), dx

Is the function you're trying to integrate here the inverse function of sin(x)? If so, it should be denoted \arcsin(x)=\sin^{-1}(x)

Homework Equations

*By Parts Formula: f(x)g(x) - \int(g(x) f'(x)) dx

This isn't a formula, since you haven't specified what it is equal to! The formula I would use is \int v du=uv-\int udv. Is this the formula you have been taught? If not, what is the formula you have been taught?

 

[crm08]

Yes, the problem is asking for the integral of arcsin(x), and also yes, that is the formula we are using, my "u's" and "v's" look a lot alike sometimes so I replaced them with f(x) and g(x), sorry about the confusion

 

[cristo]

Yes, the problem is asking for the integral of arcsin(x), and also yes, that is the formula we are using, my "u's" and "v's" look a lot alike sometimes so I replaced them with f(x) and g(x), sorry about the confusion

Ok, so your selection was u=\sin^{-1}(x) \,\, , \,\, dv=dx, right? So, what went wrong? This is the choice that I would make!

 

[crm08]

Ok nevermind I got it now, I was working towards an answer to this problem that my 89 gave me but I typed it in wrong, I see how to to it now, the answer being:

x*arcsin(x) + sqrt(1-x^2)

Thanks for your help

 

[Mark44]

Plus a constant