Jacob C. answered 06/30/21
Adaptive Math and Physics Tutor
Let u = <-2, 5, -4>, v = <1, -6, 3>, and w = <2, 3, 1>. We wish to compute ||2u + 3v - 4w||.
Compute each part of the sum independently using the scalar multiplication property of a vector.
2u = 2 <-2, 5, -4> = <-4, 10, -8>
3v = 3 <1, -6, 3> = <3, -18, 9>
4w = 4 <2, 3, 1> = <8, 12, 4>
Compute the sum directly using the addition property of vectors.
2u + 3v - 4w = <-4, 10, -8> + <3, -18, 9> - <8, 12, 4>
2u + 3v - 4w = <-4 + 3 - 8, 10 - 18 - 12, -8 + 9 - 4>
2u + 3v - 4w = <-9, -20, -3>
Compute the magnitude as the square root of the sum of the components squared.
||2u + 3v - 4w|| = √((-9)2 + (-20)2 + (-3)2)
||2u + 3v - 4w|| = √(81 + 400 + 9)
||2u + 3v - 4w|| = √(490)
||2u + 3v - 4w|| = 7√10