∫sin2xcos2x9−cos42xdx=
12cos−113cos22x+c
−14cos−113cos22x+c
−12sin−113cos22x+c
−14sin−113cos22x+c
Put cos22x=t
⇒-2sin2xcos2x2dx=dt⇒sin2xcos2x2dx=-14dt -14∫19-t4dt=-14sin-1t3+c