document.write( "Question 1191911: A circular ripple spreads across a lake. If the area of the ripple increases
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Algebra.Com's Answer #823749 by Edwin McCravy(20060)\"\" \"About 
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A circular ripple spreads across a lake. If the area of the ripple increases
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document.write( "That means \"dA%2Fdt=10pi\"\"m%5E2%2Fs\"\r\n" );
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document.write( "We want a formula for the area of a circle.\r\n" );
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document.write( "\"A=pi%2Ar%5E2\"\r\n" );
document.write( "\"dA%2Fdt=2%2Api%2Ar%2Aexpr%28dr%2Fdt%29\"\r\n" );
document.write( "Substitute \"10pi\" for \"dA%2Fdt\" and simplify

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document.write( "Substitute 2 for r\r\n" );
document.write( "Solve for \"dr%2Fdt\"\r\n" );
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document.write( "Edwin
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