Question

Vector u has its initial point at (-7, 2) and its terminal point at (11, -5). Vector v has a direction opposite that of vector u, and its magnitude is three times the magnitude of u. What is the component form of vector v?
A. v = <-54, 63>
B. v = <-162, -63>
C. v = <-54, 21>
D. v = <-162, 21>

Answer 1

$\bf u=(-7,2),(11,-5)\implies u=\stackrel{\textit{component form}}{<11-(-7),-5-2>}\implies u=<18,-7> \\\\\\ \stackrel{\textit{opposite direction of it}}{-1<18,-7>}\implies <-18,7>\implies \stackrel{\textit{3 times the magnitude}}{3<-18,7>}\implies \boxed{<-54,21>}$

Answer 2

Answer:

C. v = < -54, 21 >

Explanation:

I got it correct in my test :)