document.write( "Question 1158166: If cos(x)=1/18
\n" ); document.write( " (in Quadrant-I), find sin(2x)= \n" ); document.write( "

Algebra.Com's Answer #781089 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+sin%28+2x+%29+=+2sin%28x%29%2Acos%28x%29+\"$
\n" ); document.write( " $\"+cos%28+x+%29+=+1%2F18+\"$
\n" ); document.write( " $\"+sin%5E2%28x%29+=+1+-+cos%5E2%28x%29+\"$
\n" ); document.write( " $\"+sin%5E2%28x%29+=+1+-+%28+1%2F18+%29%5E2+\"$
\n" ); document.write( " $\"+sin%5E2%28x%29+=+1+-+1%2F324+\"$
\n" ); document.write( " $\"+sin%5E2%28x%29+=+323+%2F+324+\"$
\n" ); document.write( " $\"+sin%28x%29+=+17.9722+%2F+18+\"$
\n" ); document.write( " $\"+sin%28x%29+=+.9985+\"$
\n" ); document.write( "-------------------------
\n" ); document.write( " $\"+sin%28+2x+%29+=+2sin%28x%29%2Acos%28x%29+\"$
\n" ); document.write( " $\"+sin%28+2x+%29+=+2%2A.9985%2A%28+1%2F18+%29+\"$
\n" ); document.write( " $\"+sin%282x%29+=+.1109+\"$
\n" ); document.write( "--------------------------
\n" ); document.write( "check with calculator:
\n" ); document.write( " $\"+cos%28+x+%29+=+1%2F18+\"$
\n" ); document.write( " $\"+cos%28+x+%29+=+.05556+\"$
\n" ); document.write( " $\"+x+=+86.8153+\"$ degrees
\n" ); document.write( " $\"+2x+=+173.6305+\"$
\n" ); document.write( " $\"+sin%28+2x+%29+=+.1109+\"$
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );