The point (3, -4) lies in the quadrant 4.
The length of the vector will be = [tex] \sqrt{(3)^{2} +(4)^{2} } =5[/tex]
cos theta can be found by dividing the horizontal component of the vector (which is 3) with the length of the vector.
So,
[tex]cos(theta)= \frac{3}{5} [/tex]
