I = int ( (1 + cos4x) / (cotx + sinx) ) . dx
I = 2 int ( (cos22x) ( - sinx) / (cos2x - cosx - 1) ) . dx
Put y = cosx
so, dy = - sinx . dx
Now, I = 2 int ( (2y2 -1)2 / ( y2 - y - 1 ) . dy
I = 2 int ( (4y2)(y2 - -y - 1 + y) + 1) / ( y2 - y -1 ) ) . dy
I = 8 int y2 . dy + 8 int ( y3 / ( y2 - y - 1 ) ) . dy + 2 int ( 1 / ( y2 - y - 1 ) ) . dy
I = 8 int y2 . dy + 8 int ( 2y + 1 / ( y2 - y - 1 ) ) . dy + 8 int (y + 1) . dy+ 2 int ( 1 / ( y2 - y - 1 ) ) . dy
I = 8 int y2 . dy + 8 int ( 2y - 1 / ( y2 - y - 1 ) ) . dy + 2 int ( 1 / ( y2 - y - 1 ) ) . dy + 8 int (y + 1) . dy+ 2 int ( 1 / ( y2 - y - 1 ) ) . dy
Now, you can integrate. If you still have any problem nudge me.