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

  1. Chapter 10 Class 12 Vector Algebra (Term 2)
  2. Serial order wise

Transcript

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
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.