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document.write( "241° is between 180° and 270° which is the third quadrant, QIII. That's\r\n" );
document.write( "the lower left quadrant. 241° has this terminal side and the red arc\r\n" );
document.write( "shows its counter-clockwise rotation from the right had side of the x-axis.\r\n" );
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document.write( "Notice that 241° is made up of two angles of rotation. The 180° rotation \r\n" );
document.write( "(in green) and the rotation after 180° which is 241°-180° = 61° (in blue):\r\n" );
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document.write( "So the angle indicated by the blue arc, between the x-axis and the terminal\r\n" );
document.write( "side is 61°, and we say that \"the reference angle of 241° is 61°\". This\r\n" );
document.write( "REFERENCE angle has the same sine, cosine, and tangent as 241² except for\r\n" );
document.write( "their positive and negative signs. [There is a problem here because \"sine\" and\r\n" );
document.write( "\"sign\" are pronounced the same. So we'll say \"positive-ness and negative-ness\"\r\n" );
document.write( "to avoid confusion between the two words when we talk about the positive-ness or\r\n" );
document.write( "negative-ness of the trig rations and functions.] \r\n" );
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document.write( "Now learn the sentence: \"All Students Take Calculus\" to remember \"All S T C\"\r\n" );
document.write( "For the quadrants, think of this as though it were an x,y coordinate system:\r\n" );
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document.write( " S|A\r\n" );
document.write( " T|C\r\n" );
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document.write( "The major three trig functions are Sine, Cosine, and Tangent, the others\r\n" );
document.write( "are their reciprocals. This memory device only works with the major three\r\n" );
document.write( "trig functions, Sine, Cosine and Tangent.\r\n" );
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document.write( "\"All\" reminds us that ALL trig functions are POSITIVE in the first quadrant QI.\r\n" );
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document.write( "\"STUDENTS\" reminds us that of the major three trig functions, the SINE is\r\n" );
document.write( "POSITIVE in the second quadrant QII, and the other two major trig functions are\r\n" );
document.write( "NEGATIVE there.\r\n" );
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document.write( "\"TAKE\" reminds us that of the major three trig functions, the TANGENT is\r\n" );
document.write( "POSITIVE in the third quadrant QIII, and the other two major trig functions are\r\n" );
document.write( "NEGATIVE there.\r\n" );
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document.write( "\"CALCULUS\" reminds us that of the major three trig functions, the COSINE is\r\n" );
document.write( "POSITIVE in the fourth quadrant QIV, and the other two major trig functions are\r\n" );
document.write( "NEGATIVE there.\r\n" );
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document.write( "If the major trig function, the SINE, is positive or negative in a quadrant, its\r\n" );
document.write( "reciprocal, the COSECANT is also positive or negative there.\r\n" );
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document.write( "If the major trig function, the COSINE, is positive or negative in a quadrant,\r\n" );
document.write( "its reciprocal, the SECANT is also positive or negative there.\r\n" );
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document.write( "If the major trig function, the TANGENT, is positive or negative in a quadrant,\r\n" );
document.write( "its reciprocal, the COTANGENT is also positive or negative there.\r\n" );
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document.write( "Now if we have learned that, let's go through what this information tells us\r\n" );
document.write( "about the positive-ness or negative-ness of cos(241°).\r\n" );
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document.write( "The cosine is negative in the third quadrant, QIII. But the cosine of the\r\n" );
document.write( "reference angle is always positive, because if place in proper position it\r\n" );
document.write( "would always be in the first quadrant QI where all trig rations and functions\r\n" );
document.write( "are positive. So to get the answer to this problem, simply put a negative\r\n" );
document.write( "in front of cos(61°) and that's your answer:\r\n" );
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document.write( "Answer: cos(241°) = -cos(61°)\r\n" );
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document.write( "Edwin
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