wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

The number of straight lines that are equally inclined to the three-dimensional co-ordinate axis, is


A

2

No worries! We‘ve got your back. Try BYJU‘S free classes today!
B

4

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C

6

No worries! We‘ve got your back. Try BYJU‘S free classes today!
D

8

No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B

4


Explanation for the correct option:

Assume α,β,γ are the angles made by the line with x,y, and z-axis, respectively, then

cos2α+cos2β+cos2γ=1

we have given α=β=γ

3cos2α=1cosα=±13

Possible direction cosines are ±13,±13,±13.

Different direction cosines are 13,13,13,13,13,-13,13,-13,13and -13,13,13.

Thus, 4 lines are equally inclined to axes.

Hence, option (B) is the correct answer.


flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon