document.write( "Question 1205835: Solve the following equations for all x, unless the domain is restricted.\r
\n" ); document.write( "\n" ); document.write( "cos(1/2x) = 1/2\r
\n" ); document.write( "\n" ); document.write( "A. 2𝛑/3, + 2𝛑n
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\n" ); document.write( "E. 3𝛑/4 + 2𝛑n
\n" ); document.write( "F. 𝛑/2
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Algebra.Com's Answer #842903 by ikleyn(52943) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "Your starting equation is \r\n" );
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document.write( "    cos(1/2x) = 1/2    (1)\r\n" );
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document.write( "Cosine is positive in QI and QIV.\r\n" );
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document.write( "Equation (1) has two sets of solutions.  One set is in QI\r\n" );
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document.write( "     = .    (2)\r\n" );
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document.write( "The other set of solutions is in QIV\r\n" );
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document.write( "     = .   (3)\r\n" );
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document.write( "Accordingly, we have two sets of solutions for x.  From (2), we have this set\r\n" );
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document.write( "    x = .     (4)\r\n" );
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document.write( "From (3), we have this set\r\n" );
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document.write( "    x = .    (5)\r\n" );
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document.write( "ANSWER. The solutions to the given equation are these two sets of angles\r\n" );
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document.write( "            x =   and  x = .\r\n" );
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document.write( "        These sets have no intersections.\r\n" );
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\n" ); document.write( "\n" ); document.write( "No one of these (true) answer sets is presented in your answer list - - - so, your answer list is DEFECTIVE.\r
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