# Math Help - conv. and div. by comparison

1. ## conv. and div. by comparison

just a question:

while using comparisons to decide whether the integral converges or diverges

we know that 1/x div
1/x^2 conv
what about 1/x^3 and 1/x^4???????

2. Originally Posted by alex83
just a question:

while using comparisons to decide whether the integral converges or diverges

we know that 1/x div
1/x^2 conv
what about 1/x^3 and 1/x^4???????
ask yourself this question for $x>1$

how are the two functions related.

$\frac{1}{x^2}$ and $\frac{1}{x^3}=\frac{1}{x^2}\frac{1}{x}$

Which do you think is smaller