Question

Решить уравнение: sin2x * cos2x = -1/4 

Answer 1

$sin2x * cos2x = -frac {1}{4};2sin2x * cos2x =-frac{2}{4}; sin (2*2x) = -frac{1}{2}; sin 4x=-0.5; 4x=(-1)^k*(-frac{pi}{6})+pi*k; 4x=(-1)^{k+1}*(frac{pi}{6})+pi*k; x=(-1)^{k+1}*(frac{pi}{24})+frac {pi}{4}*k;$ k є Z