Question 651799
ln(z^4-z^2)


ln(z^2(z^2-1))


ln(z^2(z-1)(z+1))


ln(z^2) + ln(z-1) + ln(z+1)


2ln(z) + ln(z-1) + ln(z+1)


So the answer is 


2ln(z) + ln(z-1) + ln(z+1)