Answer:
[tex]\frac{dA}{dt} = 2\pi r(\frac{dr}{dt})[/tex]
Step-by-step explanation:
Your solution is correct (See explanation):
Area (A) of a circle is
[tex]A = \pi r^2[/tex]
Where
[tex]r = radius[/tex]
Differentiate both sides with respect to t
[tex]\frac{dA}{dt} = 2\pi r(\frac{dr}{dt})[/tex]
This is so because, we have to differentiate A on the left hand side and r on the right hand side because [tex]2\pi[/tex] is a constant
Hence, your solution is correct and and
[tex]\frac{dA}{dt} = 2\pi r(\frac{dr}{dt})[/tex]
