# Divergent or convergent

1. Feb 15, 2005

$$\int_9^{inf} \frac{1}{x^{6/5}}$$

first thing i did was found the integral of the function

$$\frac{5}{x^{-1/5}}$$

then plug in inf(i will name it b) and 9

$$\frac{5}{b^{-1/5}} - \frac{5}{9^{-1/5}}$$
now i will find the lim -> inf

well for $$\frac{5}{9^{-1/5}}$$, it's equal to 7.759

now for $$\frac{5}{b^{-1/5}}$$, it looks like INF, but when i try to submit my answer, it tells me that i'm wrong.

anyone know what i'm doing wrong?

2. Feb 15, 2005

### Muzza

The primitive function is wrong, it should be

$$-\frac{5}{x^{1/5}}$$.

3. Feb 15, 2005

### dextercioby

Therefore,not only the limit,but also the numerical value for 9 is wrong...You should have written the integrand as $x^{-\frac{6}{5}}$.

Daniel.