Integration prob

1. Nov 5, 2009

look416

1. The problem statement, all variables and given/known data

Integrate $$\int \frac{1}{x}$$ dx

2. Relevant equations

3. The attempt at a solution
using formula of integration what i got is $$\frac{1}{0}$$
which is infinity wth

2. Nov 5, 2009

tiny-tim

Hi look416!
But what are the limits of integration?

(and the integral of 1/x is logx )

3. Nov 5, 2009

look416

ops for got to put
the limits are e < x < 1

4. Nov 5, 2009

Staff: Mentor

It's not true that e < 1, so you can't have e < x < 1. The limits of integration are x = 1 and x = e, most likely, with the lower limit of integration being x = 1. If you have them in the other order you'll get a negative value for the integral.

5. Nov 5, 2009

look416

very sorry
just rechecked the question yep
its 1 < x < e
but still i have no idea to integrate it

6. Nov 5, 2009

dextercioby

Do you know any result/formula which could help you calculate $\int_{1}^{e} \frac{1}{x} \ {} dx$ ?

7. Nov 5, 2009

TheoMcCloskey

I think OP needs to review basic definition of integration of f(x)=1/x. It does not follow the "power rule" that he has inadvertly applied.