Functions Question 58

Question: If $ f(r)=\pi r^{2} $ , then $ \underset{h\to 0}{\mathop{\lim }}\frac{f(r+h)-f(r)}{h}= $

Options:

A) $ \pi r^{2} $

B) $ 2\pi r $

C) $ 2\pi $

D) $ 2\pi r^{2} $

Show Answer

Answer:

Correct Answer: B

Solution:

$ \frac{d}{dr}f(r)=2\pi r $ .