document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=522220>Question 522220</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help.  i don't know how to do this.<BR>\n" );
document.write( "I have to write the following in vertex form and tell if they open up or down.\r<BR>\n" );
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document.write( "1.The vertex of the parabola is the origin.  Point P (1,7) lies on the graph of the parabola.<BR>\n" );
document.write( "2.The vertex of the parabola is the origin.  Point W (4,-5) lies on the graph of the parabola.\r<BR>\n" );
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document.write( "Thanks so much </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #347395 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=347395\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I have to write the following in vertex form and tell if they open up or down. <BR>\n" );
document.write( "1.The vertex of the parabola is the origin. Point P (1,7) lies on the graph of the parabola.<BR>\n" );
document.write( "2.The vertex of the parabola is the origin. Point W (4,-5) lies on the graph of the parabola. <BR>\n" );
document.write( "Thanks so much<BR>\n" );
document.write( "**<BR>\n" );
document.write( "The best way to do this is plot the two given points, vertex(0,0), and given point P(1,7) on the graph. Since the y-value of the point>0, the parabola must open upwards.<BR>\n" );
document.write( "Similarly, for point W(4,-5), the y-value<0, so the parabola must open downwards. <BR>\n" );
document.write( "..<BR>\n" );
document.write( "To do it algebraically:<BR>\n" );
document.write( "Standard form of a parabola: y=A(x-h)^2+k, with (h,k) being the (x,y) coordinates of the vertex.<BR>\n" );
document.write( "Since the(x,y) coordinates of both parabolas, boil down to y=Ax^2.<BR>\n" );
document.write( "The problem is to find A for the equations of both parabolas.<BR>\n" );
document.write( "For the first problem, using (x,y) coordinates of given point (1,7)<BR>\n" );
document.write( "7=A(1^2)<BR>\n" );
document.write( "A=7<BR>\n" );
document.write( "Equation of parabola: y=7x^2<BR>\n" );
document.write( "..<BR>\n" );
document.write( "For the second problem, using (x,y) coordinates of given point (4,-5)<BR>\n" );
document.write( "-5=A(4^2)=16A<BR>\n" );
document.write( "A=-5/16<BR>\n" );
document.write( "Equation of parabola: -5x^2/16<BR>\n" );
document.write( "Plot these two equations and the first will open up and the second opens down. </SPAN>\n" );
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