document.write( "Question 770001: I have no idea how to start this problem. Ca you please help. Use a graphing utility to approximate the solutions of the equation in the interval [0, 2π). If possible, find the exact solutions algebraically. (Enter your answers as a comma-separated list.)
\n" ); document.write( "9 tan 2x − 18 cos x = 0
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Algebra.Com's Answer #469184 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "               9tan(2x) − 18cos(x) = 0\r\n" );
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document.write( "Divide through by 9\r\n" );
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document.write( "                 tan(2x) − 2cos(x) = 0\r\n" );
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document.write( "                    \"sin%282x%29%2Fcos%282x%29\" - 2cos(x) = 0\r\n" );
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document.write( "                \"%282sin%28x%29cos%28x%29%29%2F%281-2sin%5E2%28x%29%29\" - 2cos(x) = 0\r\n" );
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document.write( "Divide through by 2\r\n" );
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document.write( "                 \"%28sin%28x%29cos%28x%29%29%2F%281-2sin%5E2%28x%29%29\" - cos(x) = 0\r\n" );
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document.write( "Multiply through by LCD of 1 - 2sinē(x)\r\n" );
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document.write( "sin(x)cos(x) - cos(x)(1 - 2sinē(x)) = 0\r\n" );
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document.write( "Factor out cos(x)\r\n" );
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document.write( "     cos(x)[sin(x) - (1 - 2sinē(x)] = 0\r\n" );
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document.write( "      cos(x)[sin(x) - 1 + 2sinē(x)} = 0\r\n" );
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document.write( "Use the zero-factor property:\r\n" );
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document.write( "cos(x) = 0;            sin(x) - 1 + 2sinē(x) = 0\r\n" );
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document.write( "x = \"pi%2F2\", \"3pi%2F2\";            2sinē(x) + sin(x) - 1 = 0     \r\n" );
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document.write( "                   [2sin(x) - 1][sin(x) + 1] = 0\r\n" );
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document.write( "               2sin(x) - 1 = 0            sin(x) + 1 = 0       \r\n" );
document.write( "                   2sin(x) = 1                sin(x) = -1 \r\n" );
document.write( "                    sin(x) = \"1%2F2\"                     x = \"3pi%2F2\"\r\n" );
document.write( "                         x = \"pi%2F6\", \"5pi%2F6\"  \r\n" );
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document.write( "There are 4 solutions in  [0, 2π).\r\n" );
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document.write( "               \"pi%2F6\", \"pi%2F2\", \"5pi%2F6\", and \"3pi%2F2\"                             \r\n" );
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document.write( "Edwin
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