document.write( "Question 596101: using pythagorean identity to siplify the following expressions.
\n" ); document.write( "a) cos^2 30 degrees + sin^2 30 degrees
\n" ); document.write( "b) cos^2 50 degrees + cos^2 40 degrees
\n" ); document.write( "c) 1 - sin^2 20 degrees
\n" ); document.write( "

Algebra.Com's Answer #377656 by richard1234(7193)\"\" \"About 
You can put this solution on YOUR website!
a) 1
\n" ); document.write( "b) cos^2 (40) = sin^2 (50), 1
\n" ); document.write( "c) Rewrite 1 as sin^2 (20) + cos^2 (20), ans is cos^2 (20)
\n" ); document.write( "
\n" );