alleryDirection cosines (l, m, n) of a line satisfy:
Al = m = n
Bl² + m² + n² = 1 (unit vector property)
CAlways 0
Dl + m + n = 1
Answer & Solution
Correct answer: B. l² + m² + n² = 1 (unit vector property)
**Direction cosines:** cosines of angles the line makes with x, y, z axes.
(l, m, n) form a unit vector along the line; hence l² + m² + n² = 1.
Keep practising Unit 8A: Areas Between Curves
Browse all Unit 8A: Areas Between Curves questions for AP Calculus AB, or explore more Mathematics topics.
Related questions
Let $\mathbf{A}=\langle 1,2,3\rangle$, $\mathbf{B}=\langle 2,0,1\rangle$, and $\mathbf{C}=For nonzero vector $\mathbf{A}$, which expression gives a vector in the same direction as When subtracting vectors, $\vec A-\vec B$ is evaluated asThe projection of vector $\vec A$ on vector $\vec B$ is given byWhich statement about a null vector is correct?If $\omega$ is a non-real cube root of unity, find the value of $1 + \omega + \omega^2$.Find the modulus of the complex number $z = 3 + 4i$.The locus of the point $z$ in the Argand plane satisfying $|z - 2| = |z + 2|$ is: