Home › UP Board Class 12 › mathematics › Vectors & 3D Geometry › A UNIT VECTOR in the direction of v = 3i + 4j is:
A UNIT VECTOR in the direction of v = 3i + 4j is:
A$(3i + 4j)/5$
B$(3i + 4j)/7$
C$3i + 4j$ itself
D$5(3i + 4j)$
Answer & Solution
Correct answer: A. $(3i + 4j)/5$
|v| = √(9+16) = √25 = 5. Unit vector v̂ = v/|v| = (3i + 4j)/5 = (0.6)i + (0.8)j.
Related questions
The angle θ between two PLANES with normals n1 and n2 satisfies:A point R divides the line joining P (position vector a) and Q (position vector b) INTERNAFor direction cosines l, m, n of any line in 3D:The Cartesian equation of a plane with intercepts 2, 3, 6 on the x, y, z axes is:The vector triple product a × (b × c) simplifies via:The scalar triple product [a b c] geometrically represents:Two non-zero vectors a and b are PERPENDICULAR if and only if:If a = 2i + 3j + k and b = i − j + 2k, then a · b equals: