∫1/(y²-1) dy
=∫1/[(y+1)(y-1)] dy
=1/2 ∫[1/(y-1)-1/(y+1)] dy
=1/2[∫1/(y-1) dy-∫1/(y+1)dy]
=1/2[ln|y-1|-ln|y+1|]+C
=1/2 ln|(y-1)/(y+1)|+C
∫1/(y²-1) dy
=∫1/[(y+1)(y-1)] dy
=1/2 ∫[1/(y-1)-1/(y+1)] dy
=1/2[∫1/(y-1) dy-∫1/(y+1)dy]
=1/2[ln|y-1|-ln|y+1|]+C
=1/2 ln|(y-1)/(y+1)|+C