document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=132215>Question 132215</A>: <I><SPAN STYLE=\"word-break: break-all;\"> This is a story problem.  There are two poles, 10m and 15m high, and 25m apart on level ground.  A wire goes from the top of each pole to the bottom of the other pole.  How do you find a function that expresses the height of the intersection of the wires in terms of the heights of the two poles?  I know how to find the height of the intersection by plotting coordinates and finding the intersection of the 2 lines based on their slopes.  The height of the intersecting point is 6m.  Can you help me find the function to solve it? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #96726 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=96726\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> There are two poles, 10m and 15m high, and 25m apart on level ground.  A wire goes from the top of each pole to the bottom of the other pole.  How do you find a function that expresses the height of the intersection of the wires in terms of the heights of the two poles?  I know how to find the height of the intersection by plotting coordinates and finding the intersection of the 2 lines based on their slopes.  The height of the intersecting point is 6m.  Can you help me find the function to solve it?<BR>\n" );
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document.write( "I think you have the right idea.<BR>\n" );
document.write( "Let the 10m pole have end points (0,0) and (0,10)<BR>\n" );
document.write( "Let the 15m pole have end points (25,0) and (25,15)<BR>\n" );
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document.write( "Find the equation of the line thru (0,0) and (25,15)<BR>\n" );
document.write( "y = (15/25x or y = (3/5)x<BR>\n" );
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document.write( "Find the equation of the line thru (0,10) and (25,0)<BR>\n" );
document.write( "slope = -10/25 = -2/5 <BR>\n" );
document.write( "y=intercept is 10<BR>\n" );
document.write( "Equation is y = (-2/5)x+10<BR>\n" );
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document.write( "find the intersection of:<BR>\n" );
document.write( "y = (3/5)x and y = (-2/5)x+10<BR>\n" );
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document.write( "Substitute to solve for \"x\":<BR>\n" );
document.write( "3/5 x = -2/5x + 10<BR>\n" );
document.write( "x = 10<BR>\n" );
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document.write( "Substitute to solve for y:<BR>\n" );
document.write( "y = (3/5)10 = 6<BR>\n" );
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document.write( "Point of intersection is (10,6)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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