Last Three Problems. Log Derivatives

[scrum]

I got

y' = 1/(x^2+y^2) ( 2x+2y y' )

but then I don't know whether this is correct or how to extract the y' from part the second part.

I got

ylog(x) = xlog(y)

y' log(x) + y(1/x) = x(1/y (y')) + log(y)

then I get confused

I plug 100,000 into n and then put 1 as x and I keep getting a number suspicously close to e. I think it's ex^3 or something similar but I don't quite know how to pin it down.

 

[tkhunny]

1) Notation needs clarity. Technically, it means what you want, but you could write it more clearly. Now solve for y'

2) Sove for y'

3) Find the limit of log(1 + x/n)^n

 

[scrum]

thanks

I gotthem all except the last one but my friend helped me and it's e^x so i'm like yay.