Question

let
u = 5i - j, v = 5i + j, w = i + 2j
find the specified scalar.
(4u)·v
(4u)·v =

Explanation:

Step1: Scalar multiply vector u

$4\mathbf{u} = 4(5\mathbf{i} - \mathbf{j}) = 20\mathbf{i} - 4\mathbf{j}$

Step2: Compute dot product with v

$(4\mathbf{u}) \cdot \mathbf{v} = (20)(5) + (-4)(1)$

Step3: Calculate final scalar value

$100 - 4 = 96$

Answer:

96