What does that substitution do to the integral?What is the resulting integral?

[ana111790]

Homework Statement

Find the integral of:

[a*ln(b/(b -cx)) - kx] dx

Where all a,b,c,k are constants and x is the variable.

Homework Equations

The Attempt at a Solution

Rewrote is:
a*INT(ln(b/(b-cx)) dx) - k*INT(x dx)

I don't know how to solve the first part, (the second integral I know is kx^2/2)

Thank you for your help.

 

[xiaoB]

I don't know this for you is helpful or not ?

You can check it out form this site.

http://www.tutorvista.com/math/integral-of-log-x

 

[epenguin]

You started attack and you have to continue.

∫a*(ln(b/(b-cx)) dx) = a*∫ln(b/(b-cx) dx

You have to remember basic property of logs! You can do this if you can do ∫ ln(b - cx) dx .

And you can do that if you can do ∫ln x dx .

If y = ln x , what does x = ?

What substitution for x does that suggest?