document.write( "Question 1159951: Solve: cos(x) cos (6x) =-1 \n" ); document.write( "

Algebra.Com's Answer #783093 by ikleyn(52782) $\"\"$ $\"About$

You can put this solution on YOUR website!
.
\n" ); document.write( "

\r\n" );
document.write( "\r\n" );
document.write( "HINT.  This equation can be satisfied IF and ONLY IF  one of the two factors in left side is equal to -1, \r\n" );
document.write( "while the other factor is equal to 1.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Answer.   x =  = 180°.\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );