Question #04f88

1 Answer
Mar 8, 2017

11

Explanation:

x(sqrt(x^2+1)-sqrt(x^2-1))=(2x)/(sqrt(x^2+1)+sqrt(x^2-1))x(x2+1x21)=2xx2+1+x21 and

(2x)/(sqrt(x^2+1)+sqrt(x^2-1))=(2x)/(x(sqrt(1+1/x^2)+sqrt(1-1/x^2)))=2xx2+1+x21=2xx(1+1x2+11x2)=

2/(sqrt(1+1/x^2)+sqrt(1-1/x^2))21+1x2+11x2 so

lim_(x->oo)x(sqrt(x^2+1)-sqrt(x^2-1))=lim_(x->oo)2/(sqrt(1+1/x^2)+sqrt(1-1/x^2))=2/2=1