Question

. Find the indicated dot product. r = <9, -7, -8>, v = <3, 4, 7>, w = <6, -9, 7> v ? w (1 point) <-27, 28, 56> <18, -36, 49> 18 31

Answer 1

31

Explanation:

v ⋅ w = (3)(6) + (4)(-9) + (7)(7)

v ⋅ w = 18 - 36 + 49

v ⋅ w = 31

Answer 2

The dot product is a scalar product, so you can eliminate the first two choices right away.

We have

`v\cdot w=\langle3,4,7\rangle\cdot\langle6,-9,7\rangle=3\cdot6+4\cdot(-9)+7\cdot7=31`