document.write( "Question 1189670: Solve the following equations for x between 0° and 360°
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document.write( "a) cosec x = -2
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document.write( "b) sec x = 5 sin 20°
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document.write( "c) cot^2 x = 3 \n" );
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Algebra.Com's Answer #821121 by Theo(13342) You can put this solution on YOUR website! a) cosec x = -2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "cosec(x) = 1/sin(x) \n" ); document.write( "equation becomes: \n" ); document.write( "1/sin(x) = -2 \n" ); document.write( "solve for sin(x) to get sin(x) = -1/2 \n" ); document.write( "sine is negative in third and fourth quadrant. \n" ); document.write( "arcsin(1/2) = 30 degrees. \n" ); document.write( "that's in the first quadrant. \n" ); document.write( "equivalent angle in the third quadrant is 180 + 30 = 210 degrees. \n" ); document.write( "equivalent angle in the fourth quadrant is 360 - 30 = 330 degrees. \n" ); document.write( "x can either be 210 degrees or 330 degrees. \n" ); document.write( "that's your solution. \n" ); document.write( "here's what it looks like in a graph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "b) sec x = 5 sin 20°\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "sec(x) = 1/cos(x) \n" ); document.write( "equation becomes: \n" ); document.write( "1/cos(x) = 5sin(20) \n" ); document.write( "solve for cos(x) to get: \n" ); document.write( "cos(x) = 1/(5sin(20)) \n" ); document.write( "use your calculator to solve for 5sin(20). \n" ); document.write( "you will get 5sin(20) = 1.710100717. \n" ); document.write( "cos(x) = 1/that = .58476088. \n" ); document.write( "solve for x to get: \n" ); document.write( "x = 54.21390092 degrees. \n" ); document.write( "that's in the first quadrant. \n" ); document.write( "cosine is positive in the first and fourth quadrant. \n" ); document.write( "equivalent angle in the fourth quadrant is 360 - 54.21390092 = 305.7860991 degrees. \n" ); document.write( "x can be either 54.21390092 and 305.7860991 degrees. \n" ); document.write( "that's your solution. \n" ); document.write( "here's what it looks like on a graph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "c) cot^2 x = 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "cot^2(x) = 1/tan^2(x) \n" ); document.write( "equation becomes: \n" ); document.write( "1/tan^2(x) = 3. \n" ); document.write( "solve for tan^2(x) to get: \n" ); document.write( "tan^2(x) = 1/3. \n" ); document.write( "solve for tan(x) to get: \n" ); document.write( "tan(x) = sqrt(1/3) \n" ); document.write( "solve for x to get: \n" ); document.write( "x = arctan(sqrt(1/3)) = 30 degrees. \n" ); document.write( "cotangent is positive in the first and third quadrant. \n" ); document.write( "cotangent is negative in the second and fourth quadrant. \n" ); document.write( "cotangent^2 is positive in all four quadrants. \n" ); document.write( "equivalent angle in the second quadrant is 180 - 30 = 150 degrees. \n" ); document.write( "equivalent angle in the third quadrant is 180 + 30 = 210 degrees. \n" ); document.write( "equivalent angle in the fourth quadrant is 360 - 30 = 330 degrees. \n" ); document.write( "x can be either 30, 150, 210, of 340 degrees. \n" ); document.write( "that's your solution. \n" ); document.write( "here's what it looks like on a graph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let me know if you have any questions.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "theo\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |