1 Not it's actually in Quadrants II and IV In Q I and III, the coordinates of the point have the same sign For instance, Quadrant I (2,4) Quadrant III (1,3)10 r ( x, y) θ O y x Definition 21 Trigonometric Functions of a General Angle Let θ be an angle in standard position and suppose that ( x , y ) is any point other than ( 0 , 0 ) on the terminal side of θ(Figure 23)If r = x2 y2 is the distance between ( x, y ) and ( 0 , 0 ), then the six trigonometric functions of θ are defined by Using similar triangles, you can see that the values With {x1,y1} = first point center point, and {x2,y2} = third point center point, the signed angle (pi,pi) is given by atan2 (x2*y1 x1*y2,x1*x2 y1*y2) Depending on your definition of the sign of the angle you may or may not want to add a minus in front You can easily derive the quadrant from sign and absolute size
Ex 3 3 1 In Which Quadrant Or On Which Axis Do Each Of
