∫cot3xcosec−8x dx
sin6x6−sin8x8+C
sin6x6+sin8x8+C
cos6x6−cos8x8+C
cos6x6+cos8x8+C
cosecx=t⇒(cosecxcotx)dx=−dt∫t2−1(−dt)t9=−∫1t7dt+∫1t9dt=16t6−18t8+C