7. let a, = (-1)" 1+n and let c, = 2a,-kak k=0 where n e nu {0}. then which one of the following is true? iit-jam 2018 (a) both a, and 2, are convegent. n=0 n=l

7. Let a, = (-1)" 1+n and let c, = 2a,-kak k=0 where n e NU {0}. Then which one of the following is TRUE? IIT-JAM 2018 (a) Both a, and 2, are convegent. n=0 n=l (b)a,, is convergent but 2c, is not n= n=0 convergent.