document.write( "Question 844373: If f(x) = log3 (x + 1), what is f−1(2)? \r
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Algebra.Com's Answer #508721 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
\"%22f%28x%29%22\"\"%22%22=%22%22\"\"log%283%2C%28x%2B1%29%29\"\r\n" );
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document.write( "Change f(x) to y\r\n" );
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document.write( "\"y\"\"%22%22=%22%22\"\"log%283%2C%28x%2B1%29%29\"\r\n" );
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document.write( "Interchange x and y\r\n" );
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document.write( "\"x\"\"%22%22=%22%22\"\"log%283%2C%28y%2B1%29%29\"\r\n" );
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document.write( "Use the principle that \"A=log%28B%2C%28C%29%29\" is equivalent to \"C=B%5EA\" \r\n" );
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document.write( "\"y%2B1\"\"%22%22=%22%22\"\"3%5Ex\"\r\n" );
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document.write( "Solve for y:\r\n" );
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document.write( "\"y\"\"%22%22=%22%22\"\"3%5Ex-1\"\r\n" );
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document.write( "Replace y by f-1(x)\r\n" );
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document.write( "f-1(x) = 3x - 1 \r\n" );
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document.write( "So substitute x=2\r\n" );
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document.write( "f-1(2) = 32 - 1 = 9 - 1 = 8\r\n" );
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document.write( "Edwin
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