document.write( "Question 159089: A farmer with 10,000 meters of fencing wants to enclose a rectangular field and then divide it into three plots with two fences parallel to one of the sides. What is the area that can be enclosed? I need to find the vertex but cannot figure out how to solve this problem. (Analyzing Graphs of Quadratic Functions). \n" ); document.write( "
Algebra.Com's Answer #117204 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
A farmer with 10,000 meters of fencing wants to enclose a rectangular field and
\n" ); document.write( " then divide it into three plots with two fences parallel to one of the sides.
\n" ); document.write( " What is the area that can be enclosed? I need to find the vertex
\n" ); document.write( ":
\n" ); document.write( "They want to find the max area that can be enclosed which is the vertex
\n" ); document.write( ":
\n" ); document.write( "Since they want three plots, we will have two lengths and four widths
\n" ); document.write( ":
\n" ); document.write( "Let L = length, Let x = the width
\n" ); document.write( ";
\n" ); document.write( "2L + 4x = 10000
\n" ); document.write( "Simplify divide by 2
\n" ); document.write( "L + 2x = 5000
\n" ); document.write( ":
\n" ); document.write( "L = (5000 - 2x)
\n" ); document.write( ";
\n" ); document.write( "Area = L*x
\n" ); document.write( "Substitute (5000-2x) for L
\n" ); document.write( "A = (5000-2x) * x
\n" ); document.write( ":
\n" ); document.write( "A quadratic equation
\n" ); document.write( "A = -2x^2 + 5000x
\n" ); document.write( ":
\n" ); document.write( "When you want to find the vertex, you don't want to simplify the equation
\n" ); document.write( ":
\n" ); document.write( "To find the vertex, find the axis of symmetry; x = -b/(2a): a=-2, b=5000
\n" ); document.write( ":
\n" ); document.write( "x = \"%28-5000%29%2F%282%2A-2%29\"
\n" ); document.write( "x = \"%28-5000%29%2F%28-4%29\"
\n" ); document.write( "x = +1250 meters is the width for max area
\n" ); document.write( ":
\n" ); document.write( "Find the max area, substitute 1250 for x in the area equation:
\n" ); document.write( "A = -2(1250^2) + 5000(1250)
\n" ); document.write( "A = -3125000 + 6250000
\n" ); document.write( "A = 3,125,000 sq meters is the max area
\n" ); document.write( ":
\n" ); document.write( "The vertex: 1250, 3,125,000
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Did this make sense to you? Any questions?
\n" ); document.write( "
\n" );