(a) f(x)=1/x² applies so the limit is 1
(b) f(x)=x+1 applies so the limit is 2
(c) f(x)=x+1 applies so the limit is 2+1=3
Sorry about the confusion. It was because I had to memorise the question to some extent since my comm device cannot show the question and my answer at the same time until I submitted it.