document.write( "Question 127713: Hi Can I have some help concerning functions?\r
\n" ); document.write( "\n" ); document.write( "A quadratic function is given.
\n" ); document.write( "f(x) = 6x^2 + x + 1
\n" ); document.write( "(a) Express the quadratic function in standard form.\r
\n" ); document.write( "\n" ); document.write( "f(x) = a(x - h)^2 + k where
\n" ); document.write( "a =
\n" ); document.write( "h =
\n" ); document.write( "k =
\n" ); document.write( "

Algebra.Com's Answer #93592 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "\n" ); document.write( "\"y=6+x%5E2%2B1+x%2B1\" Start with the given equation\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-1=6+x%5E2%2B1+x\" Subtract \"1\" from both sides\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-1=6%28x%5E2%2B%281%2F6%29x%29\" Factor out the leading coefficient \"6\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Take half of the x coefficient \"1%2F6\" to get \"1%2F12\" (ie \"%281%2F2%29%281%2F6%29=1%2F12\").\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now square \"1%2F12\" to get \"1%2F144\" (ie \"%281%2F12%29%5E2=%281%2F12%29%281%2F12%29=1%2F144\")\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-1=6%28x%5E2%2B%281%2F6%29x%2B1%2F144-1%2F144%29\" Now add and subtract this value inside the parenthesis. Doing both the addition and subtraction of \"1%2F144\" does not change the equation\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-1=6%28%28x%2B1%2F12%29%5E2-1%2F144%29\" Now factor \"x%5E2%2B%281%2F6%29x%2B1%2F144\" to get \"%28x%2B1%2F12%29%5E2\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-1=6%28x%2B1%2F12%29%5E2-6%281%2F144%29\" Distribute\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-1=6%28x%2B1%2F12%29%5E2-1%2F24\" Multiply\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=6%28x%2B1%2F12%29%5E2-1%2F24%2B1\" Now add \"1\" to both sides to isolate y\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=6%28x%2B1%2F12%29%5E2%2B23%2F24\" Combine like terms\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now the quadratic is in vertex form \"y=a%28x-h%29%5E2%2Bk\" where \"a=6\", \"h=-1%2F12\", and \"k=23%2F24\". Remember (h,k) is the vertex and \"a\" is the stretch/compression factor. Also \"a\" tells us which direction the parabola opens.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So in this case the vertex is (\"-1%2F12\",\"23%2F24\") and the parabola opens upward since \"a%3E0\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Check:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Notice if we graph the original equation \"y=6x%5E2%2B1x%2B1\" we get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C6x%5E2%2B1x%2B1%29\" Graph of \"y=6x%5E2%2B1x%2B1\". Notice how the vertex is (\"-1%2F12\",\"23%2F24\").\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Notice if we graph the final equation \"y=6%28x%2B1%2F12%29%5E2%2B23%2F24\" we get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C6%28x%2B1%2F12%29%5E2%2B23%2F24%29\" Graph of \"y=6%28x%2B1%2F12%29%5E2%2B23%2F24\". Notice how the vertex is also (\"-1%2F12\",\"23%2F24\").\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So if these two equations were graphed on the same coordinate plane, one would overlap another perfectly. So this visually verifies our answer.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );