Example 13 - Find angle between vectors  a and b, magnitudes

Example 13 - Chapter 10 Class 12 Vector Algebra - Part 2

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

Transcript

Example 13 Find the angle between two vectors ๐‘Ž โƒ— and ๐‘ โƒ— with magnitudes 1 and 2 respectively and when ๐‘Ž โƒ— โ‹…๐‘ โƒ— =1. "Given |" ๐’‚ โƒ—"| = 1 , |" ๐’ƒ โƒ—"| = 2 , " "and " ๐’‚ โƒ—". " ๐’ƒ โƒ—" = 1" We know that ๐’‚ โƒ— . ๐’ƒ โƒ— = "|" ๐’‚ โƒ—"|" "|" ๐’ƒ โƒ—"|" cos ฮธ where ฮธ is the angle between ๐‘Ž โƒ— and ๐‘ โƒ— Putting values in formula ๐‘Ž โƒ— . ๐‘ โƒ— = "|" ๐‘Ž โƒ—"|" "|" ๐‘ โƒ—"|" cos ฮธ 1 = 1 ร— 2 ร— cos ฮธ cos ฮธ = 1/2 cos ฮธ = cos ๐…/๐Ÿ‘ So, ฮธ = ๐…/๐Ÿ‘ Thus angle b/w ๐‘Ž โƒ— and ๐‘ โƒ— is ๐œ‹/3 .

About the Author

Davneet Singh's photo - Teacher, Engineer, Marketer
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.