document.write( "Question 323916: the exact value of cos(-330 degrees) is? \n" ); document.write( "

Algebra.Com's Answer #231832 by Edwin McCravy(20059) $\"\"$ $\"About$

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the exact value of cos(-330 degrees) is?
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document.write( "We start off with x and y axes:\r\n" );
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document.write( "Then we start our angle from the right side of the x-axis, and\r\n" );
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document.write( "since the angle is negative, we swing an arc in the clockwise\r\n" );
document.write( "direction through 330° and draw a radius vector:\r\n" );
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document.write( "And we see that the angle is coterminal with 30°, since one\r\n" );
document.write( "revolution is 360° and 330° subtracted from 360° is 30°,\r\n" );
document.write( "and so the reference angle is 30°, \r\n" );
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document.write( "and since -330° has its\r\n" );
document.write( "terminal side in the first quadrant, its cosine will be the\r\n" );
document.write( "same as the cosine of 30° and positive. so:\r\n" );
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document.write( "Edwin

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