Q73. If cos-1(p) + cos-1(q) + cos-1(r) = π, then the value of p2 + q2 + r2 + 2pqr is:Mathematics — NUST Mock By IBAGRADS 1 — Question 73 of 200A. 3B. 1C. 2D. -1Practice more Mathematics MCQs for entrance exam preparation on Examora.io.← Previous Question Next Question →