Differentiate a mixture of e's

**aceband** · December 7th 2009, 08:51 AM

Hi i'm just looking to see if i've got this right:

differentiate:

$\frac{e^x}{e^x+e^{-x}}$

I got this:

$\frac{2}{e^{2x}+e^{-2x}}$

Something at the back of my head says "that looks wrong" so i'm seeking clarifcation and/or guidance

Thank you

**Danny** · December 7th 2009, 09:02 AM

Originally Posted by aceband

Hi i'm just looking to see if i've got this right:

differentiate:

$\frac{e^x}{e^x+e^{-x}}$

I got this:

$\frac{2}{e^{2x}+e^{-2x}}$

Something at the back of my head says "that looks wrong" so i'm seeking clarifcation and/or guidance

Thank you

Not sure how you got the denominator. I got

$<br /> \frac{2}{\left(e^x + e^{-x}\right)^2}<br />$