Cos 45 degrees equals sin? - Answers

cos(45) = sin(45) You can see this as follows: imagine a circle with radius 1. The point on the circle with angle 45 degrees, lies on the line y=x, equally far from the x-axis (cos) as the y-axis (sin). The angle for both must be 45, because x and y are orthogonal: 90 deg, so if the angle with x is 45, then the angle with y must be 90-45=45. So: for this point, both angles are 45, and the distance to x (cos) is equal to the distance to y (sin). Therefore, cos(45) = sin(45). Additionally, cos(45) = sin(45+90) = sin(45+360n) = sin(135+360n) with n integer.