document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=584079>Question 584079</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The main cables of a suspension bridge are ideally parabolic. The cables over a bridge that is 400 feet long are attached to towers that are 100 feet tall. The lowest point of the cable is 40 feet above the bridge\r<BR>\n" );
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document.write( "a. Find the coordinatesof the vertex and the tops of the towers if the bridge represents the         x-axis and the axis of symmetry is the y-axis\r<BR>\n" );
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document.write( "b. Find the equation that can be used to model the cables </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #372676 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=372676\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The main cables of a suspension bridge are ideally parabolic. The cables over a bridge that is 400 feet long are attached to towers that are 100 feet tall. The lowest point of the cable is 40 feet above the bridge <BR>\n" );
document.write( "a. Find the coordinatesof the vertex and the tops of the towers if the bridge represents the x-axis and the axis of symmetry is the y-axis <BR>\n" );
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document.write( "vertex: (0,40)<BR>\n" );
document.write( "tower tops: (-200,100) and (200,100)<BR>\n" );
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document.write( "b. Find the equation that can be used to model the cables<BR>\n" );
document.write( "Form: ax^2 + bx + c = y<BR>\n" );
document.write( "Using (0,40):::::::  0....0...c = 40 <BR>\n" );
document.write( "Using (-200,100)::: 40000a - 200b + c = 100<BR>\n" );
document.write( "Using (200,100):::: 40000a + 200b + c = 100<BR>\n" );
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document.write( "Solve for a,b,c:<BR>\n" );
document.write( "a = 0.0015 <BR>\n" );
document.write( "b = 0<BR>\n" );
document.write( "c = 40<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "y = 0.0015x^2 + 40<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "============================ </SPAN>\n" );
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