Last updated at May 6, 2021 by Teachoo

Transcript

Example 28 (Supplementary NCERT) Find ๐ if the vectors ๐ โ = ๐ ฬ + 3๐ ฬ + ๐ ฬ, ๐ โ = 2๐ ฬ โ ๐ ฬ โ ๐ ฬ and ๐ โ = ๐๐ ฬ + 7๐ ฬ + 3๐ ฬ are coplanar.Three vectors ๐ โ, ๐ โ, ๐ โ are coplanar if [๐ โ" " ๐ โ" " ๐ โ ] = 0 Given, ๐ โ = ๐ ฬ + 3๐ ฬ + ๐ ฬ ๐ โ = 2๐ ฬ โ ๐ ฬ โ ๐ ฬ ๐ โ = ฮป๐ ฬ + 7๐ ฬ + 3๐ ฬ [๐ โ" " ๐ โ" " ๐ โ ] = |โ 8(1&3&1@2&โ1&โ1@๐&7&3)| 0 = 1[(โ1ร3)โ(7รโ1) ] โ 3[(2ร3)โ(ฮปรโ1) ] + 1[(2ร7)โ(ฮปรโ1) ] 0 = 1 [โ3โ(โ7)]โ3[6โ(โฮป)]+1[14โ(โฮป)] 0 = 1 [โ3+7]โ3[6+ฮป]+1[14+ฮป] 0 = 4 โ 18 โ 3ฮป + 14 + ฮป 0 = 18 โ 18 โ 3ฮป + ฮป 0 = โ 2ฮป โ2ฮป = 0 ฮป = 0/(โ2) ๐ = 0 Therefore, ๐ โ,๐,๐ โ are coplanar if ฮป = 0

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Example 26 (Supplementary NCERT) Deleted for CBSE Board 2022 Exams

Example 27 (Supplementary NCERT) Deleted for CBSE Board 2022 Exams

Example 28 (Supplementary NCERT) Important Deleted for CBSE Board 2022 Exams You are here

Example 29 (Supplementary NCERT) Important Deleted for CBSE Board 2022 Exams

Example 30 (Supplementary NCERT) Important Deleted for CBSE Board 2022 Exams

Example 31 (Supplementary NCERT) Important Deleted for CBSE Board 2022 Exams

About the Author

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.