# Thread: derivative problem with e^x

1. ## derivative problem with e^x

y= e ^ 5- (2/x) ............ whats the derivative? for some reason i cant find the answer!!

thanks!

2. Originally Posted by I"love"mymathteacher
y= e ^ 5- (2/x) ............ whats the derivative? for some reason i cant find the answer!!

thanks!
$y=e^{5-\frac{2}{x}}$

Use the chain rule. Whenever a composite function looks complicated like this, just introduce a variable. Let $u=5-\frac{2}{x}$. So now $y=e^u$. So now use the chain rule $\frac{dy}{dx}=\frac{dy}{du}\frac{du}{dx}$. I'll let you try to finish this, we aren't really suppose to just give answers around here. Reply with what you think the answer is, if you're still stuck, I will help you finish it.