document.write( "Question 973828: Please Help!!!!
\n" ); document.write( "Which of the following is equivalent to 1/(1-cos(x))- 1/(1+cos(x))?
\n" ); document.write( "A) 2cot(x)csc(x)
\n" ); document.write( "B) 2tan(x)sec(x)
\n" ); document.write( "C) 2+cot^2(x)
\n" ); document.write( "D) 4sec(4x)
\n" ); document.write( "E) 0\r
\n" ); document.write( "\n" ); document.write( "When I subtract I get (1+cos(x))-(1-cos(x))/(1-cos(x))(1+cos(x)). That gives me 2cos(x)/1-cos^2(x). That's all I got. I can not figure where to go from here. \n" ); document.write( "

Algebra.Com's Answer #595874 by Edwin McCravy(20059) $\"\"$ $\"About$

You can put this solution on YOUR website!

 \r\n" );
document.write( "Remember the identity: ?\r\n" );
document.write( "Subtract  from both sides and get   \r\n" );
document.write( "\r\n" );
document.write( "The right side of that shows that the denominator of what you have so far\r\n" );
document.write( "is \r\n" );
document.write( "\r\n" );
document.write( " becomes:\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Change the choices to all sines and cosines until you find\r\n" );
document.write( "which one is equivalent.  Begin with A)\r\n" );
document.write( "\r\n" );
document.write( "A) 2cot(x)csc(x)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So A) happens to be the correct choice.\r\n" );
document.write( "\r\n" );
document.write( "We were lucky to get it on the first try.  If that had not\r\n" );
document.write( "been the correct choice we would have changed the others to\r\n" );
document.write( "sines and cosines, until we found the correct choice.\r\n" );
document.write( "\r\n" );
document.write( "Edwin

\n" ); document.write( "

\n" );