$\"\"$

The radius of the circle is $\"\"$ .

(a)

Area of the circle with radius $\"\"$ is $\"\"$ .

$\"\"$ .

Differentiate on each side with respect to $\"\"$ .

$\"\"$

(b)

Radius of the oil spill increases at constant rate $\"\"$ m/sec.

That is $\"\"$ .

It is needed to find rate of change of area of spill when the radius is $\"\"$ m.

$\"\"$

Substitute $\"\"$ and $\"\"$ in above expression.

$\"\"$

$\"\"$ m²/sec.

Area of oil spill increases at a rate of $\"\"$ m²/sec.

(a) The rate of change of are of spill as time passes $\"\"$ .

(b) Area of Oil spill increases at a rate of $\"\"$ m²/sec.