document.write( "Question 1006604: what would be the solutions to (sin2x+cos2x)^2=1?
\n" ); document.write( "I know that this can be expanded to (sin2x+cos2x) (sin2x+cos2x)=1, which can be multiplied to be sin^2(4x)+2sin(2x)cos(2x)+cos^2(4x)=1. Or am I missing something here? I'm not sure what to do after this. Please help!
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Algebra.Com's Answer #622741 by ikleyn(52814)\"\" \"About 
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document.write( "Start with \r\n" );
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document.write( "\"%28sin2x+%2B+cos2x%29%5E2\" = \"sin%5E2%282x%29\" + \"2%2Asin%282x%29%2Acos%282x%29\" + \"cos%5E2%282x%29\" = 1 + 2*sin(2x)*cos(2x).\r\n" );
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document.write( "Therefore, your equation takes the form\r\n" );
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document.write( "1 + 2*sin(2x)*cos(2x) = 1,   or\r\n" );
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document.write( "2*sin(2x)*cos(2x) = 0.   (1)\r\n" );
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document.write( "Now, do you know this formula sin(2alpha) = 2*sin(alpha)*cos(alpha) ?\r\n" );
document.write( "(See the lesson Trigonometric functions of multiply argument in this site).\r\n" );
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document.write( "It reduces the equation (1) to\r\n" );
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document.write( "sin(4x) = 0.\r\n" );
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document.write( "The solution is x = \"k%2A%28pi%2F4%29\", k = 0, +/-1, +/-2, . . . \r\n" );
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document.write( "It is the solution of your original equation.\r\n" );
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