Answer
a) neither
b) parallel
c) orthogonal
Work Step by Step
a) u · v = (-5)(3) +(4)(4) + (-2)(-1) = 3 \ne 0
Hence not orthogonal.
Since u is not scaler multiple of v, hence not parallel.
b) u · v = (9)(-6) + (-6)(4) + (3)(-2) = -84 \ne 0.
Hence not orthogonal.
u= -\frac{3}{2} *v = -\frac{3}{2}(-6i+4j-2k)= 9i-6j+3k
Since, u is a scaler multiple of v. Hence, u and v are parallel.
c) u · v = (c)(c) +(c)(0) +(c)(-c) = c^{2} + 0 - c^{2} = 0
u and v are orthogonal
