Find if function is increasing or decreasing (Find the derivative)

with quotient rule

What can I do next? Or can I assume the function is decreasing now?

Re: Find if function is increasing or decreasing (Find the derivative)

Quote:

Originally Posted by

**moonman**

... what if ?

Re: Find if function is increasing or decreasing (Find the derivative)

Quote:

Originally Posted by

**skeeter** ... what if

?

If then the function would be positive...so then then the function is positive?

Re: Find if function is increasing or decreasing (Find the derivative)

no ... what does tell you about ?

Re: Find if function is increasing or decreasing (Find the derivative)

Quote:

Originally Posted by

**skeeter** no ... what does

tell you about

?

That tells me that f is increasing?

Re: Find if function is increasing or decreasing (Find the derivative)

The derivative of the function vanishes at n = 2, -2? This function cannot be monotonic. Looks to me that it has points of extrema. It can only be locally increasing or decreasing.

Re: Find if function is increasing or decreasing (Find the derivative)

So can the Integral Test be performed on this if it were a series?

Re: Find if function is increasing or decreasing (Find the derivative)

Ok, I found an error in differentiation.

Re: Find if function is increasing or decreasing (Find the derivative)

with quotient rule

always negative

Correct? Can someone please check the derivative?

Re: Find if function is increasing or decreasing (Find the derivative)

you had it correct the first time ...

the derivative is negative for and positive for