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

Transcript

Example 22 Find |๐‘Ž โƒ— ร— ๐‘ โƒ—|, if ๐‘Ž โƒ— = 2๐‘– ฬ‚ + ๐‘— ฬ‚ + 3๐‘˜ ฬ‚ and ๐‘ โƒ— = 3๐‘– ฬ‚ + 5๐‘— ฬ‚ โˆ’ 2๐‘˜ ฬ‚ Given ๐’‚ โƒ— = 2๐‘– ฬ‚ + ๐‘— ฬ‚ + 3๐‘˜ ฬ‚ ๐’ƒ โƒ— = 3๐‘– ฬ‚ + 5๐‘— ฬ‚ โˆ’ 2๐‘˜ ฬ‚ Now, ๐’‚ โƒ— ร— ๐’ƒ โƒ— = |โ– 8(๐‘– ฬ‚&๐‘— ฬ‚&๐‘˜ ฬ‚@2&1&3@3&5&โˆ’2)| = ๐‘– ฬ‚ (1 ร— (-2) โ€“ 5 ร— 3) โˆ’ ๐‘— ฬ‚ (2 ร— (-2) โˆ’ 3 ร— 3) + ๐‘˜ ฬ‚ (2 ร— 5 โˆ’ 3 ร— 1) = ๐‘– ฬ‚ (โˆ’2 โˆ’15) โˆ’ ๐‘— ฬ‚ (โˆ’4 โˆ’9) + ๐‘˜ ฬ‚ (10 โˆ’ 3) = โ€“17๐’Š ฬ‚ + 13๐’‹ ฬ‚ + 7๐’Œ ฬ‚ So, Magnitude of ๐‘Ž โƒ— ร— ๐‘ โƒ— = โˆš((โˆ’17)2+(13)2+(7)2) |๐‘Ž โƒ—" ร— " ๐‘ โƒ— | = โˆš(289+169+49) = โˆš507 Thus, |๐‘Ž โƒ—" ร— " ๐‘ โƒ— | = โˆš๐Ÿ“๐ŸŽ๐Ÿ•

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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.