document.write( "Question 160870This question is from textbook Basic Technical Mathematics
\n" ); document.write( ": Please help me :)
\n" ); document.write( "Find theta for 0 degrees less tha or equal to (\n" ); document.write( "a) tan theta= 0.932, sin theta<0
\n" ); document.write( "b) sin theta= -0.192, tan theta<0
\n" ); document.write( "c) sec theta= 2.047, cot theta <0
\n" ); document.write( "d) cot theta=-0.3256,csc theta>0\r
\n" ); document.write( "\n" ); document.write( "#50.page 243
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Algebra.Com's Answer #118576 by gonzo(654)\"\" \"About 
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a. tan theta = .932, sin theta < 0.
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\n" ); document.write( "in order for the tangent to be positive, the angle has to be in the first or third quadrant.
\n" ); document.write( "in order for the sin to be negative, the angle has to be in the third or fourth quadrant.
\n" ); document.write( "looks like the angle has to be in the third quadrant to satisfy both requirements.
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\n" ); document.write( "calculator gives theta = 42.984... degrees.
\n" ); document.write( "adding 180 to theta puts it in the third quadrant.
\n" ); document.write( "180 + theta = 222.984... degrees
\n" ); document.write( "tan 222.9842... = .932
\n" ); document.write( "sine 222.9842... = minus
\n" ); document.write( "the answer is then 180 + theta = 180 + 42.98421048 = 222.98421048.
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\n" ); document.write( "b. sin theta = -.192, tan theta < 0
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\n" ); document.write( "in order for the sine to be negative, the angle must be in the third or fourth quadrant.
\n" ); document.write( "in order for the tangent to be negative, the angle must be in the second or fourth quadrant.
\n" ); document.write( "looks like the angle has to be in the fourth quadrant to satisfy both sin and tangent requirements.
\n" ); document.write( "calculator gives theta as -11.069... degrees.
\n" ); document.write( "that's in the 4th quadrant but it's not showing the angle the way we want it.
\n" ); document.write( "to get it the way we want to show it, we need to add 360 degrees to it. -11.069... degrees + 360 degrees = 348.930... degrees.
\n" ); document.write( "sine of 348.930... = -.192
\n" ); document.write( "tangent of 348.930... is negative.
\n" ); document.write( "both requirements are satisfied.
\n" ); document.write( "angle is 348.930...
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\n" ); document.write( "c. secant theta = 2.047, cot theta < 0
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\n" ); document.write( "secant is 1/cosine.
\n" ); document.write( "in order for secant to be positive, the angle must be in the first or fourth quadrant
\n" ); document.write( "cotangent is 1/cotangent.
\n" ); document.write( "in order for cotangent to be negative, the angle must be in second or fourth quadrant.
\n" ); document.write( "looks like the angle must be in the fourth quadrant to satisfy both secant and cotangent requirements.
\n" ); document.write( "since secant is 1/cos, then cos must be 1/secant.
\n" ); document.write( "since calculator only solves for cos, we work with cosine.
\n" ); document.write( "secant is 2.047
\n" ); document.write( "1/secant equals cosine = .4885...
\n" ); document.write( "angle shows as 60.756...
\n" ); document.write( "to put it in the fourth quadrant subtract it from 360.
\n" ); document.write( "360 - 60.756... = 299.243...
\n" ); document.write( "secant of 299.243... equals 1/cosine equals 2.047 which is accurate.
\n" ); document.write( "tangent of 299.243... is negative, therefore cotangent is also negative.
\n" ); document.write( "answer is 299.243 degrees.
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\n" ); document.write( "d. cot theta = -0.3256, csc theta > 0
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\n" ); document.write( "for the cotangent to be negative, the angle must be in the second or fourth quadrant.
\n" ); document.write( "for the csc to be positive, the sin is also positive and the angle must be in the first or second quadrant.
\n" ); document.write( "this makes the angle must be in the second quadrant to satisfy both.
\n" ); document.write( "since cotangent is 1/tangent, we divide 1 by cotangent to get tangent.
\n" ); document.write( "then we can use the calculator.
\n" ); document.write( "calculator give angle as -71.964 degrees which puts it in the fourth quadrant.
\n" ); document.write( "to put it in the second quadrant, add 180 to it.
\n" ); document.write( "-71.964 + 180 = 108.035...
\n" ); document.write( "to prove this is the right angle, get the cotangent of it.
\n" ); document.write( "get the tangent and then take 1/tangent to get the cotangent.
\n" ); document.write( "that calculates to be -.3256 proving the angle is correct.
\n" ); document.write( "to get the cosecant, get the sine and then take 1/sine to get the cosecant.
\n" ); document.write( "since the sine is positive, the cosecant is also positive.
\n" ); document.write( "answer is 108.035... degrees.
\n" ); document.write( "cotantent is -.3256 and cosecant is positive.
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