$\"\"$

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The volume of spherical balloon is $\"\"$ .

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Apply derivative on each side with respect to time $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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A spherical balloon is inflated with gas at the rate $\"\"$ cm³/min.

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The speed of balloon changes with radius is $\"\"$ .

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$\"\"$

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(a) To find how fast is the radius of the balloon increasing at the instant the radius $\"\"$ cm.

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$\"\"$

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Substitute $\"\"$ cm and $\"\"$ cm^3/min in above expression.

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ cm/min.

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$\"\"$

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(b) To find how fast is the radius of the balloon increasing at the instant the radius $\"\"$ cm.

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$\"\"$

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Substitute $\"\"$ cm and $\"\"$ cm^3/min in above expression.

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$ cm/min.

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$\"\"$

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(a) The speed of balloon changes with radius $\"\"$ cm is $\"\"$ cm/min.

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(b) The speed of balloon changes with radius $\"\"$ cm is $\"\"$ cm/min.