Algebra.Com's Answer #669428 by ikleyn(52809)  You can put this solution on YOUR website! . \n" );
document.write( "Solve for 0≤theta≤360, 2cos^2 theta +5cos theta-3=0 \n" );
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document.write( " = 0,\r\n" );
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document.write( "Introduce new variable x = . Then your equation takes the form\r\n" );
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document.write( " = 0.\r\n" );
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document.write( "Apply the quadratic formula:\r\n" );
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document.write( " = = .\r\n" );
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document.write( " = , = -3.\r\n" );
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document.write( "The second root is not acceptable, since cosine must be <= 1 by modulus.\r\n" );
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document.write( "The only solution is = ,\r\n" );
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document.write( "which gives = 60 degs and/or = 300 degs.\r\n" );
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document.write( "Answer. = 60 degs and/or = 300 degs.\r\n" );
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