document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=489785>Question 489785</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need help in finding the coordinates of the vertex for the parabola defined by the given quadratic function f(x) = -x^2 -4x + 8  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #334038 by </B><A HREF=/tutors/aboutme.mpl?userid=MathTherapy><B>MathTherapy(10552)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathTherapy><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=MathTherapy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=334038\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I need help in finding the coordinates of the vertex for the parabola defined by the given quadratic function f(x) = -x^2 -4x + 8 \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "To find the axis of symmetry, or the x-coordinate of the vertex, we use the formula, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-+b%2F2a ALIGN=MIDDLE  ALT=\"-+b%2F2a\"   DISABLED_style= \"max-width:90%; height:auto;\" >, where a = - 1, and b = - 4\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "That results in: x = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-%28%28-4%29%2F%282%2A-1%29%29 ALIGN=MIDDLE  ALT=\"-%28%28-4%29%2F%282%2A-1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-%28-4%29%2F-2 ALIGN=MIDDLE  ALT=\"-%28-4%29%2F-2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = - 2\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Now, substituting - 2 for x in the equation, we get: f(x) or y = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-%28-+2%29%5E2+-+4%28-+2%29+%2B+8 ALIGN=MIDDLE  ALT=\"-%28-+2%29%5E2+-+4%28-+2%29+%2B+8\"   DISABLED_style= \"max-width:90%; height:auto;\" > ------ f(x) or y = - 4 + 8 + 8 ----- y = 12\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Since the x and y-coordinates are - 2, and 12, respectively, then the coordinates of the vertex of the parabola are (<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28-+2%29 ALIGN=MIDDLE  ALT=\"highlight_green%28-+2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%2812%29 ALIGN=MIDDLE  ALT=\"highlight_green%2812%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Send comments and “thank-yous” to MathMadEzy@aol.com </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );