document.write( "Question 1176449: Find and simplify the difference quotient for the given function.\r
\n" ); document.write( "\n" ); document.write( "f(x) = 6x2\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #803390 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "6x^2 is the same as writing \"6x%5E2\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%29+=+6x%5E2\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%2Bh%29+=+6%28x%2Bh%29%5E2\" We replace every x with x+h\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%2Bh%29+=+6%28x%5E2%2B2xh%2Bh%5E2%29\" FOIL \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%2Bh%29-f%28x%29+=+6%28x%5E2%2B2xh%2Bh%5E2%29-6x%5E2\" Subtract f(x+h) and f(x). This is the \"difference\" portion of \"difference quotient\".\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%2Bh%29-f%28x%29+=+6x%5E2%2B12xh%2B6h%5E2-6x%5E2\" Distribute\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%2Bh%29-f%28x%29+=+12xh%2B6h%5E2\" The 6x^2 terms subtract and cancel.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%28f%28x%2Bh%29-f%28x%29%29%2Fh+=+%2812xh%2B6h%5E2%29%2Fh\" Divide both sides by 'h'. This is where the \"quotient\" part comes in of \"difference quotient\".\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%28f%28x%2Bh%29-f%28x%29%29%2Fh+=+%28h%2812x%2B6h%29%29%2Fh\" Factor out h from the numerator\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%28f%28x%2Bh%29-f%28x%29%29%2Fh+=+12x%2B6h\" Cancel the pair of 'h' terms from the numerator and denominator\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Answer: \"%28f%28x%2Bh%29-f%28x%29%29%2Fh+=+12x%2B6h\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Side note: Later in calculus you'll learn that as h approaches 0, the expression 12x+6h will approach 12x. This is the derivative of f(x) = 6x^2. Keep in mind that h = 0 is not allowed, since division by zero is not allowed, but we can get closer and closer to it.
\n" ); document.write( "

\n" ); document.write( "
\n" ); document.write( "
\n" );