The cos( Command Command Summary

Returns the cosine of a real number.

Command Syntax

cos(angle)

Press [COS]

TI-83/84/+/SE

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.

``````cos(π/3)
.5```
```

In degrees:

``````cos(60)
.5```
```

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(60°)
.5```
```
``````cos(π/3ֿ¹ )
.5```
```

# 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.