WBJEE · Maths · Application of Derivatives
Twenty metres of wire is available to fence off a flower bed in the form of a circular sector. What must the radius of the circle be, if the area of the flower bed be greatest?
- A \(10 \mathrm{~m}\)
- B \(4 \mathrm{~m}\)
- C \(5 \mathrm{~m}\)
- D \(6 m\)
Answer & Solution
Correct Answer
(C) \(5 \mathrm{~m}\)
Step-by-step Solution
Detailed explanation
Let, radius \(=r\), arc length \(=\ell\) \(2 \mathrm{r}+\ell=20 \Rightarrow \ell=20-2 \mathrm{r}\)…
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