Last updated at May 29, 2018 by Teachoo

Transcript

Example 27 If + + , 2 + 5 , 3 + 2 3 and 6 are the position vectors of points A, B, C and D respectively, then find the angle between and . Deduce that and are collinear. Angle between & is given by cos = . Now, cos = . = + 4 . 2 8 + 2 3 2 6 2 = 1 2 + 4 8 1(2) 3 2 6 2 = 2 32 2 3 6 2 2 = 36 36 = 1 Since cos = 1, = 180 So, = 180 = 180 = So, angle between & is Also, Since angle between & is 180 , they are in opposite directions Since & are parallel to the same line , they are collinear.

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

Example 8

Example 9

Example 10

Example 11

Example 12

Example 13

Example 14 Important

Example 15

Example 16 Important

Example 17

Example 18

Example 19

Example 20

Example 21 Important

Example 22

Example 23 Important

Example 24 Important

Example 25 Important

Example 26

Example 27 You are here

Example 28 Important

Example 29 Important

Example 30 Important

Example 26 (Supplementary NCERT)

Example 27 (Supplementary NCERT)

Example 28 (Supplementary NCERT)

Example 29 (Supplementary NCERT)

Example 30 (Supplementary NCERT)

Example 31 (Supplementary NCERT)

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.