2. let fa,} and {b,} be sequences of real numbers defined as a, =| and for n21, a,, 4, +(-1)2. 20 , then b (a) fa,} converges to zero and {b,} is a cauchy seque

2. Let fa,} and {b,} be sequences of real numbers defined as a, =| and for n21, a,, 4, +(-1)2. 20 , Then b (a) fa,} converges to zero and {b,} is a Cauchy sequence (b) {a,} converges to a non-zero number and {b,} is a Cauchy sequence ()(a,) converges to zero and {b,} is,not a convergent sequence (d) fa,} converges to a non-zero number and {b,} is not a convergent sequence [IIT-JAM 2008-MA]