cos(θ) returns the cosine of θ, which is defined as the x-value of the point of intersection of the unit circle and a line containing the origin that makes an angle θ with the positive x-axis
The value returned depends on whether the calculator is in Radian or Degree mode. A full rotation around a circle is 2π radians, which is equal to 360°. The conversion from radians to degrees is angle*180/π and from degrees to radians is angle*π/180. The cos( command also works on a list of real numbers.
- ERR:DATA TYPE is thrown if you supply a matrix or a complex argument.
- ERR:ARGUMENT is thrown if you use more than one number.