10. What is the cosine of the angle between the vectors
|
A. –3/4 |
B. 1/150 |
C. 31/2/15 |
|
D. 1/2 |
E. 2 |
Solution: The answer is C
The cosine of the angle, alpha, between any two vectors a and b is defined as,
Where the numerator is the dot product of a and b and the denominator is the product of the magnitudes of a and b.
The dot product of the given vectors is,
The product of the magnitudes of the given vectors is,
So that the cosine of the angle between the two vectors is,
