If a line makes angles $90^{\circ}$,$135^{\circ}$,and $45^{\circ}$ with the positive directions of $X$,$Y$,and $Z$-axes respectively,then its direction cosines are:

  • A
    $\left(0, -\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}\right)$
  • B
    $\left(0, \frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}\right)$
  • C
    $\left(0, -\frac{1}{\sqrt{2}}, -\frac{1}{\sqrt{2}}\right)$
  • D
    $\left(0, \frac{1}{\sqrt{2}}, -\frac{1}{\sqrt{2}}\right)$

Explore More

Similar Questions

The projections of a line on the coordinate axes are $2, 3, 6$. Then the length of the line is

If the direction cosines of a line are $\left(\frac{a}{\sqrt{83}}, \frac{5}{\sqrt{83}}, \frac{c}{\sqrt{83}}\right)$ and $c-a=4$,then $ca=$

If the direction cosines of two lines are such that $2l + m + 2n = 0$ and $3l^2 + 5m^2 - 11n^2 = 0$,then the angle between the two lines is

If the direction cosines of two lines are such that $l+m+n=0$ and $l^2+m^2-n^2=0$,then the angle between them is

If a variable line in two adjacent positions has direction cosines $l, m, n$ and $l+\delta l, m+\delta m, n+\delta n,$ show that the small angle $\delta \theta$ between the two positions is given by $\delta \theta^{2}=\delta l^{2}+\delta m^{2}+\delta n^{2}$.

Difficult
View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo