Answer:
A
Explanation:
Given
u = <6, -1>
u = 6i-j
and
v=<7,-4>
v=7i-4j
The formula for angle is:
Let x be the angle

where ||u|| is the length and u.v is the dot product or scalar product of both vectors
So,



The calculated angle will be in radians. To find the angle in degrees:

Hence Option A is correct ..