document.write( "Question 439903: Please I need some extra help with this problems!!
\n" ); document.write( " Graphing Parabolas, for example this y= -x^2-2x+1?\r
\n" ); document.write( "\n" ); document.write( "please explain me how you do it?\r
\n" ); document.write( "\n" ); document.write( " Thanks, Brian
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #304010 by MathLover1(20849)\"\" \"About 
You can put this solution on YOUR website!
Graphing the parabola: \"+y+=+ax%5E2+%2B+bx+%2B+c\"\r
\n" ); document.write( "\n" ); document.write( " 1. Determine whether the parabola opens \"upward\" or \"downward\".\r
\n" ); document.write( "\n" ); document.write( " a. If \"a+%3E+0\", it opens \"upward\".\r
\n" ); document.write( "\n" ); document.write( " b. If \"a+%3C+0\", it opens \"downward\".\r
\n" ); document.write( "\n" ); document.write( " 2. Determine the \"vertex\".\r
\n" ); document.write( "\n" ); document.write( " a. The \"x-coordinate\" is \"-b%2F2a\"\r
\n" ); document.write( "\n" ); document.write( " b. The \"y-coordinate\" is found by substituting the \"x-coordinate\" in the equation \"+y+=+ax%5E2+%2B+bx+%2B+c\".\r
\n" ); document.write( "\n" ); document.write( " 3. Determine the \"y-intercept+\"by setting \"x+=+0\".\r
\n" ); document.write( "\n" ); document.write( " 4. Determine the \"x-intercepts\" (if any) by setting \"y+=+0\",or solving the equation
\n" ); document.write( " \"+y+=+ax%5E2+%2B+bx+%2B+c\".\r
\n" ); document.write( "\n" ); document.write( " 5. Determine two or three other points if there are no \"x-intercepts\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( ".example:\r
\n" ); document.write( "\n" ); document.write( "\"y=+-x%5E2-2x%2B1\"\r
\n" ); document.write( "\n" ); document.write( "1. \"a+%3C+0\", it opens \"downward\"\r
\n" ); document.write( "\n" ); document.write( "2. the \"vertex\".\r
\n" ); document.write( "\n" ); document.write( "a. The \"x-coordinate\" is \"-b%2F2a=-%28-2%29%2F2%28-1%29=2%2F-2=-1\"
\n" ); document.write( "b. substitute the \"x-coordinate\" in the equation \"y=+-x%5E2-2x%2B1\"\r
\n" ); document.write( "\n" ); document.write( "\"y=+-%28-1%29%5E2-2%28-1%29%2B1\"\r
\n" ); document.write( "\n" ); document.write( "\"y=+-1%2B2%2B1\"\r
\n" ); document.write( "\n" ); document.write( "\"y=+2\"\r
\n" ); document.write( "\n" ); document.write( "the \"vertex\" is at (-1,2)\r
\n" ); document.write( "\n" ); document.write( " 3. Determine the \"y-intercept+\"by setting \"x+=+0\".\r
\n" ); document.write( "\n" ); document.write( "\"y=+-%280%29%5E2-2%280%29%2B1\"\r
\n" ); document.write( "\n" ); document.write( "\"y=1\"
\n" ); document.write( "4. Determine the \"x-intercepts\" (if any) by setting \"y+=+0\",or solving the equation
\n" ); document.write( " \"y=+-x%5E2-2x%2B1\"\r
\n" ); document.write( "\n" ); document.write( "\"0=+-x%5E2-2x%2B1\".use quadratic formula\r
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\" \r
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-2%29+%2B-+sqrt%28%28-2%29%5E2-4%2A%28-1%29%2A1+%29%29%2F%282%2A%28-1%29%29+\" \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%284%2B4+%29%29%2F-2%29+\" \r
\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+sqrt%288%29%29%2F-2%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B-+2.83%29%2F-2+\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=+%282+%2B+2.83%29%2F-2+\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=+4.83%2F-2+\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=++-2.41+\"\r
\n" ); document.write( "\n" ); document.write( "or\r
\n" ); document.write( "\n" ); document.write( "\"x+=+%282+-+2.83%29%2F-2+\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=+0.83%2F-2+\"\r
\n" ); document.write( "\n" ); document.write( "\"x+=++-0.41+\"\r
\n" ); document.write( "\n" ); document.write( " 5. Determine two or three other points if there are no \"x-intercepts\"\r
\n" ); document.write( "\n" ); document.write( "since you have \"x-intercepts\", you skip this step\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "let see the graph:\r
\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C-x%5E2-2x%2B1%29+\"\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );