document.write( "Question 425631: cos( 2theta - Pi/2)= 1/2 \n" ); document.write( "

Algebra.Com's Answer #296301 by htmentor(1343) $\"\"$ $\"About$

You can put this solution on YOUR website!
Using the trigonometric identity, $\"cos%28A-pi%2F2%29+=+sin%28A%29\"$ , with $\"A=2theta\"$
\n" ); document.write( "So we are left with $\"sin%282theta%29+=+1%2F2\"$ -> $\"2theta+=+arcsin%281%2F2%29\"$
\n" ); document.write( " $\"2theta\"$ = 30 degrees, or $\"theta\"$ = 15 degrees = $\"15%2Api%2F180%29\"$ = 0.2618 radians
\n" ); document.write( " \n" ); document.write( "

\n" );