EXAMPLE 6 :If P º (8,2) and Q º (3,4), Find
Solution: P º (8,2) and Q º (3,4)
EXAMPLE 7 : A force of 30 N and a force of 10 N act on an object at an angle of
50^{0 }with respect to each other. What is the magnitude of the resultant force and what angle does the resultant
force form with the force of 30N?
Solution
Let F_{1 }be the first Force , 
F_{1 }  = 30N
Let F_{2 }be the second force, 
F_{2 }  = 10N
Let the angle between the two forces be a, and q be the angle between the force F_{1 } and the resultant force F. Given that a = 50^{0}
Using the cosine Law, F^{2}= F_{1
}^{2 } + F_{2 }^{2 }
2F_{1 } . F_{2 } cos 130^{0}
Thus the magnitude of the resultant is F = 37.225N and the resultant force F makes an angle of 11.88^{0} with the force of 30N.
