Consider f(x)=x+k−2x−1f(x) = \frac{\sqrt{x+k} - 2}{x-1}f(x)=x−1x+k−2. Find kkk such that the limit as x→1x \to 1x→1 exists.
k=1k = 1k=1
k=2k = 2k=2
k=3k = 3k=3
k=4k = 4k=4