# integration

• November 29th 2008, 03:41 AM
No Logic Sense
integration
f(x)=10/x
F(x)=???
• November 29th 2008, 04:02 AM
Krizalid
Pull back the constant and remember what the derivative of natural log. is.
• November 29th 2008, 04:04 AM
No Logic Sense
my book says:

f(x)=1/x ---> F(x)=ln(x)

But I don't see what happens to 1 and 10 in my case
• November 29th 2008, 04:19 AM
Krizalid
As I said, you can just pull out that constant, it's a property. It says $\int k\cdot f(x)\,dx=k\int f(x)\,dx.$
• November 29th 2008, 04:38 AM
No Logic Sense
Oh, so my answer is just
F(x)=ln(x)+k
???
• November 29th 2008, 05:11 AM
running-gag
No
If F(x)=ln(x)+k then f(x)=1/x

Answer is simply F(x)=10 lnx + k