document.write( "Question 977115: prove that tan t = sin 2t/1 + cos 2t and hence obtain the value of tan 15 and 45 and express the result in standard form \n" ); document.write( "

Algebra.Com's Answer #598646 by anand429(138) $\"\"$ $\"About$

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LHS=
\n" ); document.write( " $\"tan%28t%29=sin%28t%29%2Fcos%28t%29\"$
\n" ); document.write( "= $\"2%2Asin%28t%29cos%28t%29%2F%282%2Acos%5E2%28t%29%29\"$ [Multiplying Num. and Den. by 2*cos(t)]
\n" ); document.write( "= $\"sin%282t%29%2F%282%2Acos%5E2%28t%29-1%2B1%29\"$
\n" ); document.write( "= $\"sin%282t%29%2F%28cos%282t%29%2B1%29\"$
\n" ); document.write( "=RHS
\n" ); document.write( "Hence,
\n" ); document.write( "tan15 = sin30/(1+cos30)
\n" ); document.write( "= $\"%281%2F2%29%2F%281%2Bsqrt%283%29%2F2%29\"$
\n" ); document.write( "= $\"1%2F%282%2Bsqrt%283%29%29\"$
\n" ); document.write( "Also,
\n" ); document.write( "tan45 = sin90/(1+cos90)
\n" ); document.write( "= $\"1%2F%281%2B0%29\"$
\n" ); document.write( "= 1 \n" ); document.write( "

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