The cos( Command

Command Summary

Returns the cosine of a real number.

Command Syntax


Menu Location

Press [COS]

Calculator Compatibility


Token Size

1 byte

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.

In radians:


In degrees:


Advanced Uses

You can bypass the mode setting by using the ° (degree) and r (radian) symbols. These next two commands will return the same values no matter if your calculator is in degrees or radians:

cos(π/3ֿ¹ )

Error Conditions

  • 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.
  • ERR:DOMAIN is thrown if you supply an input ≥1E12.

Related Commands

See Also


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