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Question 4 (OR 1
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st
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question)
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Find the acute angle which the line with direction cosines 1/√3, 1/√6, n makes with positive direction of z-axis.

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Last updated at Sept. 24, 2021 by Teachoo

**
Question 4 (OR 1
**
**
st
**
**
question)
**

Find the acute angle which the line with direction cosines 1/√3, 1/√6, n makes with positive direction of z-axis.

Transcript

Question 4 (OR 1st question) Find the acute angle which the line with direction cosines 1/โ3, 1/โ6 , n makes with positive direction of z-axis. Given ๐ = 1/โ3 ๐ = 1/โ6 ๐ = ? We need to find n We know that ๐^2+๐^2+๐^2=1 (1/โ3)^2+(1/โ6)^2+๐^2=1 1/3+1/6+ ๐^2=1 (2 + 1)/6+ ๐^2=1 3/6+ ๐^2=1 1/2+ ๐^2=1 ๐^2=1 โ 1/2 ๐^2=1/2 n=ยฑโ(1/2) n=ยฑ1/โ2 Since we need the angle with positive direction of x-axis, We take positive value of n n = 1/โ2 We know that cos ๐พ = n cos ๐พ = 1/โ2 So, ๐พ = 45ยฐ ๐ธ = ๐ /๐ So, line makes ๐/4 angle with the positive direction of z-axis

CBSE Class 12 Sample Paper for 2019 Boards

Paper Summary

Question 1 Important

Question 2

Question 3

Question 4 (Or 1st) Important You are here

Question 4 (Or 2nd)

Question 5

Question 6

Question 7 Important

Question 8 (Or 1st) Important

Question 8 (Or 2nd)

Question 9

Question 10 (Or 1st) Important

Question 10 (Or 2nd)

Question 11 Important

Question 12 (Or 1st)

Question 12 (Or 2nd)

Question 13 (Or 1st) Important

Question 13 (Or 2nd)

Question 14 Important

Question 15

Question 16 (Or 1st)

Question 16 (Or 2nd) Important

Question 17

Question 18

Question 19 Important

Question 20 Important

Question 21 (Or 1st)

Question 21 (Or 2nd) Important

Question 22

Question 23 Important

Question 24 (Or 1st)

Question 24 (Or 2nd) Important

Question 25

Question 26 (Or 1st) Important

Question 26 (Or 2nd)

Question 27 (Or 1st) Important

Question 27 (Or 2nd) Important

Question 28

Question 29 Important

Class 12

Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

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.