document.write( "Question 177064: Solve for x on the interval given:
\n" ); document.write( "a) 2sin^2x-5cosx+1=0 [0, pie]
\n" ); document.write( "b) sinx/2=0 [-pie, pie]
\n" ); document.write( "c) cos2x=cos^2x [0, 2pie]
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #132268 by Alan3354(69443)\"\" \"About 
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Solve for x on the interval given:
\n" ); document.write( "a) 2sin^2x-5cosx+1=0 [0, pi]
\n" ); document.write( "2(1-cos^2) - 5cos + 1 = 0
\n" ); document.write( "2-2cos^2 - 5cos + 1 = 0
\n" ); document.write( "2cos^2 + 5cos - 3 = 0
\n" ); document.write( "Now it's a quadratic in cos(x)
\n" ); document.write( "cos(x) = -3, +1/2
\n" ); document.write( "Ignore the -3 (it's a complex number)
\n" ); document.write( "cos(x) = 1/x
\n" ); document.write( "x = 60º, 300º = pi/3 (not pie, pi)
\n" ); document.write( "-----------------
\n" ); document.write( "b) sinx/2=0 [-pi, pi]
\n" ); document.write( "Assuming you mean sin(x/2) and not (sin(x))/2:
\n" ); document.write( "x/2 = 0, pi, -pi
\n" ); document.write( "x = 0
\n" ); document.write( "----------------
\n" ); document.write( "c) cos2x=cos^2x [0, 2pi]
\n" ); document.write( "cos^2 - cos = 0
\n" ); document.write( "cos(cos - 1) = 0
\n" ); document.write( "cos = 0, cos = 1
\n" ); document.write( "For cos(x) = 0:
\n" ); document.write( "x = pi/2, 3pi/2
\n" ); document.write( "--------------
\n" ); document.write( "For cos(x) = 1:
\n" ); document.write( "x = 0, 2pi \n" ); document.write( "
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