First slide

Direction ratios and direction cosines

Question

The distance of point $(2, 3, 4)$ from the x-axis is $k$ . The direction ratios of the line joining two points $(k + 1, k - 3, k), (1, - 3, 0)$ are

Very Easy

A

$(5, 5, 5)$
B

$(1, 1, 1)$
C

$(k^{2}, k^{2}, k^{2})$
D

$(2, 3, 4)$

Solution

The length of the distance from the point $P (a, b, c)$ from $x -$ axis is $\sqrt{b^{2} + c^{2}}$
Hence, $k = \sqrt{3^{2} + 4^{2}} = 5$
The given points are $(6, 2, 5), (1, - 3, 0)$
The direction ratios of the line joining the points $A (x_{1}, y_{1}, z_{1})$ and $B (x_{1}, y_{1}, z_{1})$ is $〈x_{2} - x_{1}, y_{2} - y_{1}, z_{2} - z_{1}〉$
Therefore, the direction ratios of the line joining the points $(6, 2, 5), (1, - 3, 0)$ is $〈- 5, - 5, - 5〉 = 〈1, 1, 1〉$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App