Question

find the derivative during delta/first principl method of f(r) = pie(r)^2

Answer 1

i'm not sure exactly what the delta/first principle method is, but the derivative of pie r squared is
\[2\pi r\]

Answer 2

that i know its 2pie r
I needed to do it in this way
y= pr^2 p= pie
y+ dy= p(r+dr)^2
now we need do find
dy/dr,
hot to proceed

Answer 3

\[\frac{dy}{dr}=\lim_{h \rightarrow 0} \pi \frac{((r+h)^2 - r^2)}{h}\]\[\lim_{h \rightarrow 0} \pi \frac{((r^2+2rh+h^2) - r^2)}{h}\]\[\lim_{h \rightarrow 0} \pi \frac{h(2r+h)}{h}\]\[\lim_{h \rightarrow 0} \pi (2r+h)\]\[ \pi (2r+0)\]\[ \pi (2r)\]
Sorry, I've missed all the equal signs

Answer 4

Sorry, but can you explain?

Answer 5

I hope this would help. I thought that was the latex problem.Sorry again if I've brought you some troubles

Answer 6

i'm not quite sure what you're asking, i'm sorry :( :(

Answer 7

I GOT IT THANKS