document.write( "Question 1055984: Can you help me in solving this problem:
\n" ); document.write( "Starting with the graph of y=2x, write the equation of the graph that results from \r
\n" ); document.write( "\n" ); document.write( "(a) reflecting about the line y=4
\n" ); document.write( "(b) reflecting about the line x=2
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Algebra.Com's Answer #671169 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
(a)
\n" ); document.write( "The reflection about \"+y+=+4+\" ( a horizontal line )
\n" ); document.write( "Must be \"+4+%2B+4+=+8+\" units along y-axis from ( 0,0 )
\n" ); document.write( "which \"+y+=+2x+\" goes through
\n" ); document.write( "This point is ( 0, 8 )
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\n" ); document.write( "The intercept at \"+y+=+4+\" is
\n" ); document.write( "\"+y+=+2x+\"
\n" ); document.write( "\"+4+=+2x+\"
\n" ); document.write( "\"+x+=+2+\"
\n" ); document.write( "( 2,4 ) , which stays the same for reflected line
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\n" ); document.write( "The slope goes through these 2 points and must have
\n" ); document.write( "the negative of the slope of the given line.
\n" ); document.write( "Now use the general point-slope formula
\n" ); document.write( "\"+%28+y+-+4+%29+%2F+%28+x+-+2+%29+=+%28+8+-+4+%29+%2F+%28+0+-+2+%29+\"
\n" ); document.write( "\"+%28+y+-+4+%29+%2F+%28+x+-+2+%29+=+4+%2F+%28-2%29+\"
\n" ); document.write( "\"+%28+y+-+4+%29+%2F+%28+x+-+2+%29+=+-2+\"
\n" ); document.write( "\"+y+-+4+=+-2%2A%28+x+-+2+%29+\"
\n" ); document.write( "\"+y+-+4+=+-2x+%2B+4+\"
\n" ); document.write( "\"+y+=+-2x+%2B+8+\"
\n" ); document.write( "( note that I get the correct slope, \"+-2+\" )
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\n" ); document.write( "Here's the plot of the 2 lines:
\n" ); document.write( "\"+graph%28+400%2C+400%2C+-10%2C+10%2C+-10%2C+10%2C+2x%2C+4%2C+-2x+%2B+8+%29+\"
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\n" ); document.write( "(b)
\n" ); document.write( "Reflected about \"+x+=+2+\"
\n" ); document.write( "This is a vertical line through ( 2, 0 )
\n" ); document.write( "The reflection of ( 0,0 ) would be ( 4,0 )
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\n" ); document.write( "\"+y+=+2x+\" intercepts \"+x=2+\" at ( 2,4 )
\n" ); document.write( "The reflection is at the same point ( 2,4 )
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\n" ); document.write( "Again, I should end up with \"+-2+\" for a slope
\n" ); document.write( "Use general point-slope formula
\n" ); document.write( "\"+%28+y+-+0+%29+%2F+%28+x+-+4+%29+=+%28+4+-+0+%29+%2F+%28+2+-+4+%29+\"
\n" ); document.write( "\"+y+%2F+%28+x+-+4+%29+=+4%2F%28-2%29+\"
\n" ); document.write( "\"+y+%2F+%28+x+-+4+%29+=+-2+\"
\n" ); document.write( "\"+y+=+-2%2A%28+x+-+4+%29+\"
\n" ); document.write( "\"+y+=+-2x+%2B+8+\"
\n" ); document.write( "This is the same line as in previous problem.
\n" ); document.write( "so, it doesn't matter whether you use \"+y+=+4+\"
\n" ); document.write( "of \"+x+=+2+\" for a reflection.
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\n" ); document.write( "Definitely get a 2nd opinion on this, it looks right
\n" ); document.write( "to me, but it's a little tricky\r
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