document.write( "Question 1157185: Find the inverse of the function
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Algebra.Com's Answer #780025 by Edwin McCravy(20060) $\"\"$ $\"About$

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document.write( "The above two solutions are incorrect.\r\n" );
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\n" ); document.write( "Find the inverse of the function
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That's this parabola with the dotted part discarded.\r\n" );
document.write( "We want to find its inverse:\r\n" );
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document.write( "So f(x) is this graph:\r\n" );
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document.write( "We want to find the equation of its inverse, the blue graph below, \r\n" );
document.write( "which is the projection of f(x) across the \"identity line\", which is \r\n" );
document.write( "the green dotted line below through the origin that leans right at \r\n" );
document.write( "am angle of 45°, and that has equation y=x.\r\n" );
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document.write( "To find the equation for the graph of the blue curve,\r\n" );
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document.write( "Step 1. Change f(x) to y\r\n" );
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document.write( "Step 2. Interchange x and y\r\n" );
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document.write( "Step 3. Solve for y\r\n" );
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document.write( "Swap sides:\r\n" );
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document.write( "Use quadratic formula with a=1, b=2, c=-1-x\r\n" );
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document.write( "We must require that y > 0, and therefore\r\n" );
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document.write( "This tells us that we can only use the + sign:\r\n" );
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document.write( "Square both sides:\r\n" );
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document.write( "So equation of the blue curve is\r\n" );
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document.write( "Step 4.  Finally, change y to f^-1(x)\r\n" );
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document.write( "Edwin

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