document.write( "Question 234312: please help prove: [sin(y/2)+cos(y/2)]^2^=1+siny \n" ); document.write( "
Algebra.Com's Answer #172782 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "\"%28Sin%28y%2F2%29%2BCos%28y%2F2%29%29%5E2=1%2BSin%28y%29\"\r\n" );
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document.write( "Square the left side:\r\n" );
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document.write( "\"Sin%5E2%28y%2F2%29%2B2%2ASin%28y%2F2%29Cos%28y%2F2%29%2BCos%5E2%28y%2F2%29=1%2BSin%28y%29\"\r\n" );
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document.write( "Swap the last two terms on the left side:\r\n" );
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document.write( "\"Sin%5E2%28y%2F2%29%2BCos%5E2%28y%2F2%29%2B2%2ASin%28y%2F2%29Cos%28y%2F2%29=1%2BSin%28y%29\"\r\n" );
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document.write( "Use the identity \"Sin%5E2%28phi%29%2BCos%5E2%28phi%29=1\" to replace\r\n" );
document.write( "the first two terms by 1.\r\n" );
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document.write( "\"1%2B2%2ASin%28y%2F2%29Cos%28y%2F2%29=1%2BSin%28y%29\"\r\n" );
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document.write( "Use the identity \"Sin%282%2Aphi%29=2%2ASin%28phi%29%2ACos%28phi%29\" to replace\r\n" );
document.write( "the second term on the left by \"Sin%282%2A%28y%2F2%29%29\" \r\n" );
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document.write( "\"1%2BSin%282%2A%28y%2F2%29%29=1%2BSin%28y%29\"\r\n" );
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document.write( "\"1%2BSin%28cross%282%29%2A%28y%2Fcross%282%29%29%29=1%2BSin%28y%29\"\r\n" );
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document.write( "\"1%2BSin%28y%29=1%2BSin%28y%29\"\r\n" );
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document.write( "Edwin
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