Sign in
Please select an account to continue using cracku.in
↓ →
Join Our JEE Preparation Group
Prep with like-minded aspirants; Get access to free daily tests and study material.
The projections of a vector on the three coordinate axis are $$6, -3, 2$$ respectively. The direction cosines of the vector are
1. Identify the Vector Components
The projections of a vector on the coordinate axes represent its Cartesian scalar components.
Let the vector be given as $$\vec{A}$$:
$$\vec{A} = 6\hat{i} - 3\hat{j} + 2\hat{k}$$
2. Calculate the Magnitude of the Vector
Find the total length of the vector using the three-dimensional distance formula:
$$|\vec{A}| = \sqrt{(6)^2 + (-3)^2 + (2)^2}$$
$$|\vec{A}| = \sqrt{36 + 9 + 4}$$
$$|\vec{A}| = \sqrt{49} = 7$$
3. Determine the Direction Cosines
The direction cosines $$(l, m, n)$$ are found by dividing each component by the vector magnitude:
$$l = \frac{6}{7}$$
$$m = -\frac{3}{7}$$
$$n = \frac{2}{7}$$
Final Answer
The direction cosines of the vector are $$\frac{6}{7}, -\frac{3}{7}, \frac{2}{7}$$.
Create a FREE account and get:
Educational materials for JEE preparation