The rate of change of area with respect to circumference is dCdA when radius is 6 cm.
For a circle with radius r:
Area: A=πr2
Circumference: C=2πr
Using the chain rule:
dCdA=drdA×dCdr
Finding drdA:
A=πr2
drdA=2πr
Finding dCdr:
C=2πr
drdC=2π
dCdr=2π1
dCdA=drdA×dCdr
dCdA=2πr×2π1
dCdA=r
At r=6 cm:
dCdA=6 cm
Therefore, the rate of change of area with respect to circumference is 6 cm.