Form a right angle triangle joining both given points to the origin, we get:
Perpendicular = 2 ( distance is always positive)
Base = 4 ( same logic)
Applying Pythagorus theorem
Hypotenuse = root of ( perpendicular squared + base squared)
Hypotenuse = root of 20 = 2 * root 5
Using x instead of theta
Sin x = perpendicular/hypotenuse
Cos x = base/hypotenuse
Sin x = -1/ root 5
Cos x = -2/ root 5
High probability of this answer being wrong.
Double check recommended.
