document.write( "Question 750980: how do you complete the square to put in the form f(x)= a(x-h)^2 +k\r
\n" ); document.write( "\n" ); document.write( "f(x)=-x^2+4x-5
\n" ); document.write( "

Algebra.Com's Answer #456941 by josgarithmetic(39625)\"\" \"About 
You can put this solution on YOUR website!
You would add a term and subtract the same term, allowing you to convert part of the expression into a factorable square trinomial. Your given function would be handled this way:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-x%5E2%2B4x-5=-1%2A%28x%5E2-4x%2B5%29\", factor a -1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "See the non-square part which is \"x%5E2-4x\", which can be factored into \"x%28x-4%29\". This is like a representation of a rectangle of x by (x-4) area. You could imagine cutting the longer length to leave a square area, cut the extra piece in half and put one of them along the other neighboring side of the square piece. A drawing would be better, as would be found in a few intermediate algebra books. Anyway, you will notice a missing square corner. THAT represents the term to both add and subtract symbolically.\r
\n" ); document.write( "\n" ); document.write( "Continuing....\r
\n" ); document.write( "\n" ); document.write( "You want \"%28-4%2F2%29%5E2=4\". This is that missing square term.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-1%2A%28x%5E2-4x%2B5%29=-1%2A%28x%5E2-4x%2B4%2B5-4%29\"
\n" ); document.write( "=\"-1%2A%28%28x-2%29%5E2%2B5-4%29\"
\n" ); document.write( "=\"-1%2A%28%28x-2%29%5E2%2B1%29\"
\n" ); document.write( "=\"-1%2A%28x-2%29%5E2-1\", square completed.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The standard form for your function is \"highlight%28f%28x%29=-1%28x-2%29%5E2-1%29\"\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );