document.write( "Question 1204736: If
\n" ); document.write( "sin(x) =
\n" ); document.write( "1
\n" ); document.write( "5
\n" ); document.write( " and x is in quadrant I, find the exact values of the expressions without solving for x.
\n" ); document.write( "(a) sin(2x)
\n" ); document.write( " \r
\n" ); document.write( "\n" ); document.write( "(b) cos(2x)
\n" ); document.write( " \r
\n" ); document.write( "\n" ); document.write( "(c) tan(2x)
\n" ); document.write( "

Algebra.Com's Answer #841188 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "\n" ); document.write( "If
\n" ); document.write( "\"sin%28x%29+=1%2F5\"\r
\n" ); document.write( "\n" ); document.write( "and \"x+\"is in quadrant I, find the exact values of the expressions without solving for \"x\"\r
\n" ); document.write( "\n" ); document.write( "in quadrant I sin, cos, and tan are positive\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"sin%28x%29+=1%2F5\"=>\"a%2Fc=1%2F5\" => \"a=1+\"and \"c=5\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "using Pythagorean theorem,\r
\n" ); document.write( "\n" ); document.write( "\"b=sqrt%285%5E2-1%5E2%29\"\r
\n" ); document.write( "\n" ); document.write( "\"b=sqrt%2824%29\"\r
\n" ); document.write( "\n" ); document.write( "\"b=sqrt%284%2A6%29\"\r
\n" ); document.write( "\n" ); document.write( "\"b=2sqrt%286%29\" or \"b=-2sqrt%286%29\"\r
\n" ); document.write( "\n" ); document.write( "we need positive value\r
\n" ); document.write( "\n" ); document.write( "\"b=2sqrt%286%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "then \"cos%28x%29=%282sqrt%286%29%29%2F5\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(a) \r
\n" ); document.write( "\n" ); document.write( "\"sin%282x%29=2cos%28x%29%2A+sin%28x%29\"\r
\n" ); document.write( "\n" ); document.write( "\"sin%282x%29=2%28%282sqrt%286%29%29%2F5%29+%2A%281%2F5%29\"\r
\n" ); document.write( "\n" ); document.write( "\"sin%282x%29=%284sqrt%286%29%29%2F25\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(b) \r
\n" ); document.write( "\n" ); document.write( "\"cos%282x%29=cos%5E2%28x%29+-+sin%5E2%28x%29\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%282x%29=%28%282sqrt%286%29%29%2F5%29%5E2+-+%281%2F5%29%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%282x%29=24%2F25-+1%2F25\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%282x%29=23%2F25\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(c) \r
\n" ); document.write( "\n" ); document.write( "\"tan%282x%29=sin%282x%29%2Fcos%282x%29\"\r
\n" ); document.write( "\n" ); document.write( "\"tan%282x%29=%28%284sqrt%286%29%29%2F25%29%2F%2823%2F25%29\"\r
\n" ); document.write( "\n" ); document.write( "\"tan%282x%29=%284sqrt%286%29%29%2F23\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );