Question

Find the inner product for (5, 2)×(-3, 7) and state whether the vectors are perpendicular. a. 1; no b. 1; yes c. -1; no d. -1; yes

Answer 1

c. -1; no

Explanation:

The inner product of 2 vector (a,b) and (c,d) is:

(a,b)(c,d) = a*c + b*d

If the inner product is equal to 0, the vectors are perpendicular.

So, the inner product of (5,2) and (-3,7) is equal to:

(5, 2)×(-3, 7) = 5(-3) + 2(7) = -1

The inner product is -1, it is different to 0, so the vectors are not perpendicular.