Question

A flower bed is made in the shape of sector of cricle.20m of wire is available to make a fence for flower bed.Find the radius of circle so that area of flower bed is maximum​

Answer 1

hope this helps you !!!!

Answer:

radius = 25

Step-by-step explanation:

Let M be the angle, the arc of the sector AOB makes with the center O. Let OA = OB = radius r.

Given

OA+arcAB+OB=20

2r+rM=20

M=20−2rr

Area A of the sector =M2r2=10r−r2

dAdr=10−2r=0

r=5

Second derivative is negative for r=5

We get maximum area at r=5

A=25

[not to bribe but do mark it as the barinlest answer if you feel so]