evaluate the limit

as lim goes to -1
(x^2 +2x +1)/ (x^4 -1)

the answer is zero but i don't know how to get it

factor thenumerator

(x+1)^2
over (x^2-1)(x^2+1)= (x+1)(x-1)(x^2+1)

so the numerator over the denominator is
(x+1)/(x-1)(x^2+1) and thelimit as x>>-1 is zero.