document.write( "Question 963565: sec 780° + cos(-540°) + sin 630° \n" ); document.write( "
Algebra.Com's Answer #588665 by Edwin McCravy(20086)\"\" \"About 
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document.write( "sec(780°) + cos(-540°) + sin(630°)\r\n" );
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document.write( "Any angle which is more than 360° can be reduced to a\r\n" );
document.write( "smaller angle with the same trig functions by dividing \r\n" );
document.write( "by 360° and taking the remainder, so \r\n" );
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document.write( "      2               1               1 \r\n" );
document.write( "360)780         360)540         360)630\r\n" );
document.write( "    720             360             360\r\n" );
document.write( "     60             180             270\r\n" );
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document.write( "So the problem reduces to\r\n" );
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document.write( "sec(60°) + cos(-180°) + sin(270°) \r\n" );
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document.write( "Since cos(-q) = cos(q),\r\n" );
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document.write( "sec(60°) + cos(180°) + sin(270°)\r\n" );
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document.write( "The secant is the reciprocal of the cosine and cos(60°) = 1/2. So\r\n" );
document.write( "sec(60°) = 2, cos(180°) = -1 and sin(270°) = -1, and the above is\r\n" );
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document.write( "2 + (-1) + (-1) = 0\r\n" );
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document.write( "Edwin
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