document.write( "Question 65913: 
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document.write( "Prove that this equation is an identity:\r\n" );
document.write( "                                ?  \r\n" );
document.write( "(sinx + cscx)² + (cosx + secx)² º tan²x + cot²x + 7
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Algebra.Com's Answer #46680 by uma(370)\"\" \"About 
You can put this solution on YOUR website!
Consider the left hand side.
\n" ); document.write( "(sinx + cosecx)^2 + (cosx + secx)^2
\n" ); document.write( "= sin^2 x + cosec^2 x + 2sinx cosecx + cos^2 x + sec^2 x + 2cosx secx\r
\n" ); document.write( "\n" ); document.write( "= (sin^2 x + cos^2 x) + (cosec^2 x + sec^2 x) + 2 + 2 [grouping and sinx*cosecx = 1, secx*cosx=1]\r
\n" ); document.write( "\n" ); document.write( "= 1 + (1 + cot^2 x + 1 + tan^2 x) + 4 [using 1 + tan^2 x = sec^2 x and so on]\r
\n" ); document.write( "\n" ); document.write( "= cot^2 x + cosec^2 x + 7\r
\n" ); document.write( "\n" ); document.write( "= Right hand side.\r
\n" ); document.write( "\n" ); document.write( "Hence the proof.\r
\n" ); document.write( "\n" ); document.write( "Good Luck!!! \n" ); document.write( "
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