document.write( "Question 826459: Okay, so I am stuck with Paul's truck company which hauls oversized loads. The trucks travel through a tunnel with an opening in the shape of a parabola that is 12 meters wide and 6 meters high.\r
\n" ); document.write( "\n" ); document.write( "I am told to find a function, T(x), for the shape of the tunnel...I am also supposed to graph it but I don't think that would be much of a trouble if I get a walk-in thus far.\r
\n" ); document.write( "\n" ); document.write( "I appreciate your help in advance, and I will be looking forward to your reply soon. Thanks a bunch! :)
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Algebra.Com's Answer #498085 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
I can say that this is a parabola that looks like a bowl
\n" ); document.write( "turned upside down. To simplify, say it is symmetric
\n" ); document.write( "about the origin. That means it intersects the x-axis
\n" ); document.write( "at ( 6,0 ) and ( -6,0 ) The T-intercept is at ( 0,6 ).
\n" ); document.write( "-------------------------------------------
\n" ); document.write( "The general form of the parabola is:
\n" ); document.write( "\"+T%28x%29+=+-a%2Ax%5E2+%2B+b%2Ax+%2B+c+\"
\n" ); document.write( "The formula for the vertex is:
\n" ); document.write( "\"+x%5Bv%5D+=+-b%2F%282a%29+\"
\n" ); document.write( "Since the vertex is on the y-axis,
\n" ); document.write( "\"+x%5Bv%5D+=+0+\"
\n" ); document.write( "I can say:
\n" ); document.write( "\"+T%28x%29+=+-a%2A0%5E2+%2B+b%2A0+%2B+c+\"
\n" ); document.write( "\"+y%5Bv%5D+=+6+\"
\n" ); document.write( "\"+6+=+c+\"
\n" ); document.write( "-----------
\n" ); document.write( "So far, I have:
\n" ); document.write( "\"+T%28x%29+=+-a%2Ax%5E2+%2B+b%2Ax+%2B+6+\"
\n" ); document.write( "Plug in ( 6,0 )
\n" ); document.write( "\"+0+=+-a%2A6%5E2+%2B+b%2A6+%2B+6+\"
\n" ); document.write( "\"+-36a+%2B+6b+%2B+6+=+0+\"
\n" ); document.write( "\"+-6a+%2B+b+%2B+1+=+0+\"
\n" ); document.write( "(1) \"+-6a+%2B+b+=+-1+\"
\n" ); document.write( "also
\n" ); document.write( "Plug in (-6,0 )
\n" ); document.write( "\"+T%28x%29+=+-a%2A%28-6%29%5E2+%2B+b%2A%28-6%29+%2B+6+\"
\n" ); document.write( "\"+0+=+-36a+-+6b+%2B+6+\"
\n" ); document.write( "\"+-36a+-+6b+%2B+6+=+0+\"
\n" ); document.write( "\"+-6a+-+b+%2B+1+=+0+\"
\n" ); document.write( "(2) \"+-6a+-+b+=+-1+\"
\n" ); document.write( "Add (1) and (2)
\n" ); document.write( "(1) \"+-6a+%2B+b+=+-1+\"
\n" ); document.write( "(2) \"+-6a+-+b+=+-1+\"
\n" ); document.write( "\"+-12a+=+-2+\"
\n" ); document.write( "\"+a+=+1%2F6+\"
\n" ); document.write( "-------------
\n" ); document.write( "Plug this back in:
\n" ); document.write( "(1) \"+-6%2A%281%2F6%29+%2B+b+=+-1+\"
\n" ); document.write( "(1) \"+-1+%2B+b+=+-1+\"
\n" ); document.write( "(1) \"+b+=+0+\"
\n" ); document.write( "--------------
\n" ); document.write( "So, the equation is:
\n" ); document.write( "\"+T%28x%29+=+-%281%2F6%29%2Ax%5E2+%2B+6+=+0+\"
\n" ); document.write( "Here's the plot:
\n" ); document.write( "\"+graph%28+400%2C+400%2C+-8%2C+8%2C+-2%2C+8%2C+-%281%2F6%29%2Ax%5E2+%2B+6+%29+\"\r
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