10 meters of wire is available to fence off a flower bed in the form of a circular sector. What must the radius of the circle in meters be, if we wish to have a flower bed with the greatest possible surface area?
Choose the correct answer.
A) 5/2  B) 2√5  C) 5  D) 4√2  E) none of these
5/2rea of Sector, 5/2 = x/360*pi*r^2   Circumference of the sector = 10   =&gt; x/360*2*pi*r +2r= 20   =&gt; 25/2/r+2r=10 OR 25/2 +2r^2=10r   =&gt; 5/2= r5-r^2   = r5-r^2   We will now max using derivations   i.e 5-2r=0   r=5/2   5/2
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10 meters of wire is available to fence off a flower bed in the form of a circular sector. What must the radius of the circle in meters be, if we wish to have a flower bed with the greatest possible surface area?