document.write( "Question 1189671: determine all values of x in the interval [0,2pi)
\n" ); document.write( "a) cotx=8 b) cscx=-3 c) secx=7 \n" ); document.write( "
Algebra.Com's Answer #821103 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Use a TI-84 calculator.\r\n" );
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document.write( "Since the interval is [0,2π) and not [0,360o), make sure the\r\n" );
document.write( "calculator is in radian mode.  Press MODE, and make sure RADIAN is highlighted\r\n" );
document.write( "and not DEGREE. If not, scroll to RADIAN and press ENTER. Press 2ND MODE to get\r\n" );
document.write( "back to the main screen.\r\n" );
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document.write( "First we'll find each values in QI, then we'll find the value in the other\r\n" );
document.write( "quadrant.\r\n" );
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document.write( "The calculator doesn't handle the reciprocal trig ratios, which are\r\n" );
document.write( "cotangent, cosecant, and secant directly.  It only handles sine, \r\n" );
document.write( "cosine, and tangent directly. The others are found from them.\r\n" );
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document.write( "a) cot(x) = 8\r\n" );
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document.write( "8 is positive and the cotangent is positive in QI and QIII.\r\n" );
document.write( "We always find the QI value first.\r\n" );
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document.write( "We must first convert cotangent of 8 to a tangent \r\n" );
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document.write( "Press 8 \r\n" );
document.write( "Press x-1\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 0.125\r\n" );
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document.write( "Then take the inverse tangent of that:\"\r\n" );
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document.write( "Press 2ND \r\n" );
document.write( "Press TAN\r\n" );
document.write( "Type 0.125\r\n" );
document.write( "Press )\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 0.1243549945   <--that's the QI value for a)\r\n" );
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document.write( "We want the QI value, so 0.1243549945 is one of the answers to a).\r\n" );
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document.write( "But we also want the QIII value, so we add to π\r\n" );
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document.write( "But we also want the QIII value, so we add π\r\n" );
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document.write( "Press + 2ND ^\r\n" );
document.write( "Your screen should read Ans+π\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 3.265947648   <--that's the QIII answer.\r\n" );
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document.write( "b) cscx=-3 \r\n" );
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document.write( "-3 is negative and the cosecant is negative in QIII and QIV.\r\n" );
document.write( "We always find the QI value first.\r\n" );
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document.write( "We must first convert cosecant, which is -3 to a sine \r\n" );
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document.write( "Press 3      <--NOTE: press 3, not -3 (3 is the absolute value of -3) \r\n" );
document.write( "Press x-1\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 0.3333333333\r\n" );
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document.write( "Then take the inverse sine of that:\"\r\n" );
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document.write( "Press 2ND \r\n" );
document.write( "Press SIN\r\n" );
document.write( "Type 0.3333333333\r\n" );
document.write( "Press )\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 0.3398369094   <--that's the QI value, which we don't want.\r\n" );
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document.write( "We want the QIII value, so we add π\r\n" );
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document.write( "Press + 2ND ^\r\n" );
document.write( "Your screen should read Ans+π\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 3.481429563   <--that's the QIII answer.\r\n" );
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document.write( "But we also want the QIV value, so we subtract from 2π\r\n" );
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document.write( "Press 2 2ND ^ - 0.3398369094 \r\n" );
document.write( "You should read \r\n" );
document.write( "2π-0.3398369094\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 5.943348398   <--that's the QIV answer.\r\n" );
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document.write( "c) sec(x) = 7\r\n" );
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document.write( "7 is positive and the secant is positive in QI and QIV.\r\n" );
document.write( "We always find the QI value first.\r\n" );
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document.write( "We must first convert the secant, 8, to a cosine \r\n" );
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document.write( "Press 7\r\n" );
document.write( "Press x-1\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 0.1428571429\r\n" );
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document.write( "Then take the inverse cosine of that:\"\r\n" );
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document.write( "Press 2ND \r\n" );
document.write( "Press COS\r\n" );
document.write( "Type 0.1428571429\r\n" );
document.write( "Press )\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 1.427448758   <--that's the QI value for c)\r\n" );
document.write( "\r\n" );
document.write( "We want the QI value, so 1.427448758 is one of the answers to c).\r\n" );
document.write( "\r\n" );
document.write( "But we also want the QIV value, so we subtract from 2π\r\n" );
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document.write( "Press 2 2ND ^ - 1.427448758 \r\n" );
document.write( "You should read \r\n" );
document.write( "2π-1.47448758\r\n" );
document.write( "Press ENTER\r\n" );
document.write( "Read 4.855736549   <--that's the QIV answer.\r\n" );
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document.write( "Edwin

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