document.write( "Question 741244: Find all solutions in the interval [0, 2pi)
\n" ); document.write( "Cos^2 (x/2) = cos^2 x \n" ); document.write( "

Algebra.Com's Answer #452100 by lwsshak3(11628) $\"\"$ $\"About$

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Find all solutions in the interval [0, 2pi)
\n" ); document.write( "Cos^2 (x/2) = cos^2 x
\n" ); document.write( " $\"cos%5E2%28x%2F2%29=cos%5E2%28x%29\"$
\n" ); document.write( " $\"cos%28x%2F2%29=sqrt%28%281%2Bcos%28x%29%29%2F2%29%29\"$
\n" ); document.write( " $\"%281%2Bcos%28x%29%29%2F2=cos%5E2%28x%29\"$
\n" ); document.write( "2cos^2(x)-cos(x)-1=0
\n" ); document.write( "(2cos(x)+1)(cos(x)-1)=0
\n" ); document.write( "cos(x)=-1/2
\n" ); document.write( "x=2π/3, 4π/3 (in Q2 and Q3 where cos<0)
\n" ); document.write( "cos(x)-1=0
\n" ); document.write( "cos(x)=1
\n" ); document.write( "x=0 \n" ); document.write( "

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