If , prove that f is continuous in its domain.
So,
Pick any > 0. Take any sequence { xn } converging to c. Then there exists an integer N such that
| xn - c | < /5|f(xn)-(5 c - 6)| = |5xn-6-5c+6| = 5|xn-c|<
then,
My question is, why do we have |xn - c | < /5? Why not |xn - c | < ? Where did the 5 come from?
Thanks.