document.write( "Question 756234: How do I find the possible angles for theta if the equation is cos theta=sin (theta/2)? \n" ); document.write( "

Algebra.Com's Answer #460197 by lwsshak3(11628) $\"\"$ $\"About$

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How do I find the possible angles for theta if the equation is
\n" ); document.write( "cos theta=sin (theta/2)
\n" ); document.write( "cosx=sin(x/2)
\n" ); document.write( " $\"cos%28x%29=sqrt%28%281-cos%28x%29%29%2F2%29\"$
\n" ); document.write( "square both sides
\n" ); document.write( " $\"cos%5E2%28x%29=+%281-cos%28x%29%29%2F2%29\"$
\n" ); document.write( " $\"2cos%5E2%28x%29=1-cos%28x%29\"$
\n" ); document.write( " $\"2cos%5E2%28x%29%2Bcos%28x%29-1=0\"$
\n" ); document.write( "(2cos(x)-1)(cos(x)+1)=0
\n" ); document.write( "2cos(x)-1=0
\n" ); document.write( "cos(x)=1/2
\n" ); document.write( "x=π/3+2πn, 5π/3+2πn, n=integer
\n" ); document.write( "or
\n" ); document.write( "cos(x)+1=0
\n" ); document.write( "cos(x)=-1
\n" ); document.write( "x=π+2πn, n=integer
\n" ); document.write( " \n" ); document.write( "

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