If A=[p22p] and A3=125, then find the value of p.Answer: p=±3SolutionUse the property ∣An∣=∣A∣n, so ∣A3∣=∣A∣3=125, giving ∣A∣=5.Now ∣A∣=p2−4, hencep2−4=5 ⇒ p2=9 ⇒ p=±3.p=±3CBSE Class 12 Board · 2019 · Subjective