document.write( "Question 1014504: The line 2x-y=5 turns about the point on it, whose ordinate and abscissae are equal, through an angle of 45°, in anti clockwise direction. Find the equation of line in the new position \n" ); document.write( "
Algebra.Com's Answer #630781 by Theo(13342)\"\" \"About 
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not sure how you're supposed to solve this, but this is how i did it.\r
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\n" ); document.write( "\n" ); document.write( "your original equation is 2x - y = 5\r
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\n" ); document.write( "\n" ); document.write( "solve for y to get y = 2x - 5\r
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\n" ); document.write( "\n" ); document.write( "since the slope intercept form of the equation of a straight line is y = mx + b, and the slope is m and the y-intercept is b, then your slope is 2.\r
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\n" ); document.write( "\n" ); document.write( "that's also the tangent of the angle between your line and a horizontal line that goes through any point on your line.\r
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\n" ); document.write( "\n" ); document.write( "so you have tangent (theta) = 2.\r
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\n" ); document.write( "\n" ); document.write( "that makes the angle theta equal to 63.42494882 degrees.\r
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\n" ); document.write( "\n" ); document.write( "now you are at the point (5,5).\r
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\n" ); document.write( "\n" ); document.write( "draw a horizontal line through it and draw the line of your equation through it.\r
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\n" ); document.write( "\n" ); document.write( "now, if you rotate that line an additional 45 degrees in an anti-clockwise direction, the angle between the horizontal line and your new line will be 65... + 45 = 108.4349494882 degrees.\r
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\n" ); document.write( "\n" ); document.write( "that means that the tangent of your new line will be tangent (108.4349494882).\r
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\n" ); document.write( "\n" ); document.write( "solve for that to get your new tangent equals -3.\r
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\n" ); document.write( "\n" ); document.write( "that means the slope of your new line is equal to -3.\r
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\n" ); document.write( "\n" ); document.write( "the slope intercept form of an equation for a straight line is y = mx + b\r
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\n" ); document.write( "\n" ); document.write( "m is the slope and b is the y intercept.\r
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\n" ); document.write( "\n" ); document.write( "when the slope is -3, the equation becomes y = -3x + b\r
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\n" ); document.write( "\n" ); document.write( "you need to find b.\r
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\n" ); document.write( "\n" ); document.write( "when y = -3x + b goes through the point (5,5), you can replace y with 5 and x with 5 to get:\r
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\n" ); document.write( "\n" ); document.write( "5 = -3*5 + b\r
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\n" ); document.write( "\n" ); document.write( "solve for b to get b = 20\r
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\n" ); document.write( "\n" ); document.write( "the equation of your new line is y = -3x + 20.\r
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\n" ); document.write( "\n" ); document.write( "it will intersect with your oirignal line at (5,5) and the angle between it and the original line will be 45 degrees.\r
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\n" ); document.write( "\n" ); document.write( "the graph of your original line and the new line is shown below:\r
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