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Example 26 (Supplementary NCERT) - Find a.(b x c), if a = 2i + j + 3k

Example 26 (Supplementary NCERT) - Chapter 10 Class 12 Vector Algebra - Part 2

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Example 26 (Supplementary NCERT) Find π‘Ž βƒ—.(𝑏 βƒ— Γ— 𝑐 βƒ—), if π‘Ž βƒ— = 2𝑖 Μ‚ + 𝑗 Μ‚ + 3π‘˜ Μ‚ , 𝑏 βƒ— = –𝑖 Μ‚ + 2𝑗 Μ‚ + π‘˜ Μ‚ , 𝑐 βƒ— = 3𝑖 Μ‚ + 𝑗 Μ‚ + 2π‘˜ Μ‚Given, 𝒂 βƒ— = 2𝑖 Μ‚ + 𝑗 Μ‚ + 3π‘˜ Μ‚ , 𝒃 βƒ— = –𝑖 Μ‚ + 2𝑗 Μ‚ + π‘˜ Μ‚ , 𝒄 βƒ— = 3𝑖 Μ‚ + 𝑗 Μ‚ + 2π‘˜ Μ‚ 𝒂 βƒ—.(𝒃 βƒ— Γ— 𝒄 βƒ—) = [π‘Ž βƒ—" " 𝑏 βƒ—" " 𝑐 βƒ— ] = |β– 8(𝟐&𝟏&πŸ‘@βˆ’πŸ&𝟐&𝟏@πŸ‘&𝟏&𝟐)| = 2[(2Γ—2)βˆ’(1Γ—1) ] βˆ’ 1[(βˆ’1Γ—2)βˆ’(3Γ—1) ] + 3[(βˆ’1Γ—1)βˆ’(3Γ—2)] = 2 [4βˆ’1]βˆ’1(βˆ’2βˆ’3)+3[βˆ’1βˆ’6] = 2(3) – 1(–5) + 3(–7) = 6 + 5 – 21 = 11 – 21 = – 10 ∴ π‘Ž βƒ—.(𝑏 βƒ— Γ— 𝑐 βƒ—) = –10

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.