Math Chapter Wise Complex Integration, Cauchy's Theorem And Calculus Of Residue English MCQ OPSC PGT 2017 Q.Necessary condition for an arc z = z(t) (a ≤ t ≤ b) to be smooth, is a: AContinuous z′(t) BIntegrable z(t) CDifferentiable z(t) DHarmonic z(t) Show answer Correct answer: Continuous z′(t)