document.write( "Question 645794: question 1
\n" ); document.write( "Solve the equation 2 cos2 x + cos x − 1 = 0, 0 ≤ x ≤ 2π. \n" ); document.write( "

Algebra.Com's Answer #405666 by lwsshak3(11628) $\"\"$ $\"About$

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Solve the equation 2 cos2 x + cos x − 1 = 0, 0 ≤ x ≤ 2π.
\n" ); document.write( "2cos^2x+cosx-1=0
\n" ); document.write( "(2cosx-1)(cosx+1)=0
\n" ); document.write( "..
\n" ); document.write( "2cosx-1=0
\n" ); document.write( "cosx=1/2
\n" ); document.write( "x=π/3,5π/3
\n" ); document.write( "or
\n" ); document.write( "cosx+1=0
\n" ); document.write( "cosx=-1
\n" ); document.write( "x=π \n" ); document.write( "

\n" );