Q44. If A is the matrix [[a, 1], [1, b]] and A + I is a singular matrix, then which of the following conditions must be true?Mathematics — NUST Mock By Dogers 5 — Question 44 of 200A. a + b = 0B. a - b = 0C. a + b + ab = 0D. ab - 1 = 0Practice more Mathematics MCQs for entrance exam preparation on Examora.io.← Previous Question Next Question →