(sinx-2cos)/(sinx+3cosx)=2sinxcosx

(sinx-2cos)/(sinx+3cosx)=2sinxcosx

普遍的な式は、tan X=Yを、sin(2X)=2Y/(1+Y^2)(sinx-2cosx)/(sinx+3cosx)=2対共にcosx(tanx-2)/(tanx+3)=2tanx-2=2(tanx+3)tanx=-8sinx*cosx=(1/2)*sin(2x)=(1/2)*2...