document.write( "Question 872206: what are the coordinates of R, the image p(1,3) under counter clockwise rotation 90 degrees about the origin? \n" ); document.write( "
Algebra.Com's Answer #526011 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "I'll do it for (2,3).  You do it for (1,3)\r\n" );
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document.write( "What we'll show is that rotation of 90° counterclockwise \r\n" );
document.write( "swaps the coordinates and changes the sign of the new \r\n" );
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document.write( "\"matrix%287%2C1%2C%0D%0AOn%2C+graph%2C+paper%2C+plot%2C+the%2C+point%2C+%22%282%2C3%29%22%29\"\r\n" );
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document.write( "As I said above, the thing to observe is that:\r\n" );
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document.write( "1. Rotation of 90° counterclockwise swaps the coordinates\r\n" );
document.write( "and changes the sign of the new x-coordinate.\r\n" );
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document.write( "(2,3) became (-3,2)\r\n" );
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document.write( "Do the same thing clockwise and you'll find:\r\n" );
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document.write( "2. Rotation of 90° clockwise swaps the coordinates and\r\n" );
document.write( "changes the sign of the new y-coordinate.\r\n" );
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document.write( "(2,3) will become (3,-2)\r\n" );
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document.write( "Edwin

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