document.write( "Question 1003700: given ∆ABC is isosceles with angleB = angleC, show that 2cotA = tanB - cotB \n" ); document.write( "
Algebra.Com's Answer #620383 by Edwin McCravy(20060)\"\" \"About 
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document.write( "\"2cot%28A%29+=+tan%28B%29+-+cot%28B%29\"\r\n" );
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document.write( "We work with the left side.\r\n" );
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document.write( "given isosceles triangle ABC, with B = C we have:\r\n" );
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document.write( "A+B+C = 180°\r\n" );
document.write( "A+B+B = 180°\r\n" );
document.write( "A+2B = 180°\r\n" );
document.write( "A = 180° - 2B\r\n" );
document.write( "cot(A) = cot(180°-2B) = -cot(2B)\r\n" );
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document.write( "So the left side\r\n" );
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document.write( "\"2cot%28A%29\"  becomes\r\n" );
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document.write( "\"-2cot%282B%29\"\r\n" );
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document.write( "\"-2%28cos%282B%29%2Fsin%282B%29%29\"\r\n" );
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document.write( "\"-2%28%28cos%5E2%28B%29-sin%5E2%28B%29%29%2F%282sin%28B%29cos%28B%29%29%29\"\r\n" );
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document.write( "\"-%28%28cos%5E2%28B%29-sin%5E2%28B%29%29%2F%28sin%28B%29cos%28B%29%29%29\"\r\n" );
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document.write( "\"%28-cos%5E2%28B%29%2Bsin%5E2%28B%29%29%2F%28sin%28B%29cos%28B%29%29\"\r\n" );
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document.write( "\"%28-cos%5E2%28B%29%29%2F%28sin%28B%29cos%28B%29%29\"\"%22%22%2B%22%22\"\"%28sin%5E2%28B%29%29%2F%28sin%28B%29cos%28B%29%29\"\r\n" );
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document.write( "\"%28-cos%5Ecross%282%29%28B%29%29%2F%28sin%28B%29cross%28cos%28B%29%29%29\"\"%22%22%2B%22%22\"\"%28sin%5Ecross%282%29%28B%29%29%2F%28cross%28sin%28B%29%29cos%28B%29%29\"\r\n" );
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document.write( "\"-cos%28B%29%2Fsin%28B%29%2Bsin%28B%29%2Fcos%28B%29\"\r\n" );
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document.write( "\"-cot%28B%29%2Btan%28B%29\"\r\n" );
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document.write( "\"tan%28B%29-cot%28B%29\"\r\n" );
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document.write( "Edwin
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