Q3 of 64 Page 49

3 is a zero of p(x) = 3x3 — x2 — ax — 45. Find 'a'.

Given, 3 is a zero of p(x).


⇒ p(3) = 0


∴ 3(3)3 — (3)2 — a(3) — 45 = 0


∴ 81 – 9 – 3a – 45 = 0


∴ 3a = 27


∴ a = 9


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