Question

1/2+cos^2•3x/2-sin^2•3x/2=0

Answer 1

$frac{1}{2} + { cos( frac{3x}{2} ) }^{2} - { sin( frac{3x}{2} ) }^{2} = 0 \ { sin(x) }^{2} = 1 - { cos(x) }^{2} \ frac{1}{2} + { cos( frac{3x}{2} ) }^{2} - 1 + { cos( frac{3x}{2} ) }^{2} = 0 \ 2{ cos( frac{3x}{2} ) }^{2} = frac{1}{2} \ { cos( frac{3x}{2} ) }^{2} = frac{1}{4} \ cos( frac{3x}{2} ) = frac{1}{2} \ frac{3x}{2} = + - frac{pi}{3} + 2pi times n \ 3x = + - frac{2pi}{3} + 4pi times n \ x = + - frac{2pi}{9} + frac{4pi times n}{3}$