HELP PLEASE ASAP CALCULUS!

Question

iwanttogotostanford · Answer

please someone explain this to me fully from start to finish, i need it to study please, @sillybilly123 - can you help possibly? :-)

sillybilly123 · Answer

STEP 1

what is the formula for Area, as function of radius, for  circle

sillybilly123 · Answer

OK

online but not online

$A = \pi r^2$

$\implies \dfrac{dA}{dr} = 2 \pi r$

By Chain rule:

$\dfrac{dA}{dt} = \dfrac{dA}{dr} \cdot \dfrac{dr}{dt} $

$\implies \left. \dfrac{dA}{dt} \right|_{r = 12, \dot r = 3} = 2 \pi (12) \cdot 3 $ cm^2 / min

iwanttogotostanford · Answer

@sillybilly123 whats next? and yes sorry i was still logged on, but not actually on my computer/

iwanttogotostanford · Answer

thank yu again by the way!

sillybilly123 · Answer

what else do ya think is left to do?

iwanttogotostanford · Answer

nothing , but just double checking are you sure this is right because i will be using this to study. not doubting you, just double checking if you're 100% sure

sillybilly123 · Answer

$\checkmark$

👌

iwanttogotostanford · Answer

ok thank you! can i ask you just two more? it really helps me to study so much!

iwanttogotostanford · Answer

or maybe 1 more

sillybilly123 · Answer

can you be quick?!?!

iwanttogotostanford · Answer

yes sorry!

iwanttogotostanford · Answer

@sillybilly123 wait please come back haha :-)

sillybilly123 · Answer

Square, right

Area = side * side

So we can say:

$A = x^2$

$dA = 2 x dx$

$= 2 (12) (\pm 0.1)$

iwanttogotostanford · Answer

is that all again? that was so quick!! are you really really good at calculus then ?

sillybilly123 · Answer

Gn !!

iwanttogotostanford · Answer

thank you!!!!

iwanttogotostanford · Answer

can you help like tomorrow or something? as well?

sillybilly123 · Answer

suresy !!!

sillybilly123 · Answer

so GN !!