document.write( "Question 1158031: determine the specified trigonometric ratio for each special angle.\r
\n" ); document.write( "\n" ); document.write( "1. cos(11pi/6)
\n" ); document.write( "2.cot(5pi/4)
\n" ); document.write( "3.sec(4pi/3)
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Algebra.Com's Answer #780948 by Theo(13342)\"\" \"About 
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11pi/6 radians * 180 / pi = 11*180/6 = 11*30 = 330 degrees.
\n" ); document.write( "the angle is in the fourth quadrant.
\n" ); document.write( "the reference angle = 360 - 330 = 30 degrees.
\n" ); document.write( "cosine of 30 degrees = sqrt(3)/2
\n" ); document.write( "since the angle is in the fourth quadrant, cosine is positive, therefore the cosine of 330 degrees is sqrt(3)/2.\r
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\n" ); document.write( "\n" ); document.write( "5pi/4 radians * 180 / pi = 5 * 180 / 4 = 5 * 45 = 225 degrees.
\n" ); document.write( "the angle is in the third quadrant.
\n" ); document.write( "the reference angle is 225 - 180 = 45 degrees.
\n" ); document.write( "cotangent of 45 degrees = 1 / tangent of 45 degrees = 1
\n" ); document.write( "since the angle is in the third quadrant, cotangent is positive, therefore the cotangent of 225 degrees is 1.\r
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\n" ); document.write( "\n" ); document.write( "4pi/3 radians * 180 / pi = 4 * 180 / 3 = 4 * 60 = 240 degrees.
\n" ); document.write( "the angle is in the third quadrant.
\n" ); document.write( "the reference angle is 240 - 180 = 60 degrees.
\n" ); document.write( "secant of 60 degrees = 1 / cosine of 60 degrees = 1 / (1/2) = 2
\n" ); document.write( "since the angle is in the third quadrant, the secant is negative, therefore the secant of 240 degrees = - 2\r
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\n" ); document.write( "\n" ); document.write( "to confirm, put your calculator in radian mode and do the following:
\n" ); document.write( "cos(11pi/6)
\n" ); document.write( "1/tan(5pi/4)
\n" ); document.write( "1/cos(4pi/3)\r
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\n" ); document.write( "\n" ); document.write( "you will get:
\n" ); document.write( "cos(11pi/6) = .8660254038
\n" ); document.write( "1/tan(5pi/4) = 1
\n" ); document.write( "1/cos(4pi/3) = -2\r
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\n" ); document.write( "\n" ); document.write( "enter sqrt(3)/2 in your calculator to find that it is equivalent to .8660254038 in decimal format.\r
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