we will define the X and Y Coordinate points on the Unit Circle X2 + Y2 = r2 (Pythagorean Theorem) r = Radius of the Circle = Hypotenuse of the Triangle 135°-90°=45° For Θ = 45°, we have X = 1*cos45° = √2/2 and Y = 1*sin45° = √2/2
for belonging to 2 quadrant the X and Y Coordinate points (-√2/2,√2/2)