# How can I integrate by parts this one?

• glomar
In summary, the conversation discusses solving an integral with a function that does not have an antiderivative and the possibility of a typo in the problem. The suggested solution by one person may not be correct due to the function not strictly converging towards infinity and the possibility of a typo in the problem.

## Homework Statement

I have to solve the following integral

1/(sqrt[x] * ln[x]) from 2 to infinity

## The Attempt at a Solution

u= ln[x] dv=1/sqrt(x)
du= 1/x v= 2 sqrt(x)

If I do this I get

lim (ln b/ sqrt[x] - 4 sqrt[x] - ln2/sqrt[x] + 4 sqrt[x])

Is this the actual result of the integral? Did I substitute correctly?

I don't think $$\int \frac{dx}{\sqrt{x}*ln(x)}$$ has an antiderivative.

Do you mean $$\int \frac{ln(x)}{\sqrt{x}}dx$$ ?

glomar said:

## Homework Statement

I have to solve the following integral

1/(sqrt[x] * ln[x]) from 2 to infinity

## The Attempt at a Solution

u= ln[x] dv=1/sqrt(x)
du= 1/x v= 2 sqrt(x)

If I do this I get

lim (ln b/ sqrt[x] - 4 sqrt[x] - ln2/sqrt[x] + 4 sqrt[x])

Is this the actual result of the integral? Did I substitute correctly?