解下列三角方程式:tanx+tan2x=tan3x.
已知cosx=(1-(M+1)sin2x)/(1+(M-1)sin2x),求x的值.
英:Solute the equation汉:解方程sin4θ+sinθ=0
Find all the positive angles less than 380° which satisfy the equation sinx+sin2xsin3x = 0.
Find all the positive angles less than 360° which satisfy the equation:cos2x+cosx+1=0
解方程式 arctan2x + arctan4x = arctan3x