Question

let v=(2, 8) and w=(-1, -4) which of the following is true? check all that apply A.) V*W= -34 B.) V and W are perpendicular C.) V=-2W D.) the x- component of V is 2

Answer 1

The TRUE answers are:

1) v= -2w

2) The x component of v is 2

3) v • w = -34

Explanation:

The only one that’s not correct is the one saying that v and w are perpendicular because when you evaluate the dot product it does not equal zero.

Answer 2

A) Assuming V*W means the dot-product of V and W, this is TRUE.
.. 2*(-1) +8*(-4) = -2 -32 = -34

B) The dot-product is shown to be non-zero, so the vectors are NOT perpendicular. B is FALSE.

C) -2W = (2, 8) = V, so this is TRUE.

D) If you call the components (x, y), then the first (x) component of V is 2, TRUE.