Puts the calculator in Degree mode.

Degree

While editing a program, press:

- MODE to access the mode menu.
- Use arrows and ENTER to select Degree.

TI-83/84/+/SE

1 byte

The `Degree` command puts the calculator into Degree mode, where the inputs and/or outputs to trig functions are assumed to be degree angles.

Angles measured in degrees range from 0 to 360, with 0 being an empty angle, 90 being a right angle, 180 being a straight angle, and 360 being a full angle all the way around a circle.

To convert from a radian angle to a degree angle, multiply by 180/π. To go the other way, and get a radian angle from a degree angle, multiply by π/180.

The following commands are affected by whether the calculator is in `Radian` or `Degree` mode:

The input is differently interpreted:

The output is differently expressed:

However, some commands are notably unaffected by angle mode, even though they involve angles, and this may cause confusion. This happens with the `SinReg` command, which assumes that the calculator is in `Radian` mode even when it's not. As a result, the regression model it generates will graph incorrectly in `Degree` mode.

Also, complex numbers in polar form are an endless source of confusion. The `angle(` command, as well as the polar display format, are affected by angle mode. However, complex exponentials (see the `e^(` command), defined as $e^{i\theta}=\cos\theta+i\sin\theta$, are evaluated as though in Radian mode, regardless of the angle mode. This gives mysterious results like the following:

```
Degree:re^θi
Done
e^(πi)
1e^(180i)
Ans=e^(180i)
0 (false)
```

Overall, it's better to put your calculator in `Radian` mode when dealing with polar form of complex numbers, especially since no mathematician would ever use degrees for the purpose anyway.

# Optimization

It's sometimes beneficial to use the `°` symbol instead of switching to `Degree` mode. The ° symbol will make sure a number is interpreted as a degree angle, even in `Radian` mode, so that, for example:

```
Radian
Done
sin(90)
-.8011526357
sin(90°)
1
```

This is smaller when only one trig calculation needs to be done. Also, it doesn't change the user's settings, which are good to preserve whenever possible.

# Related Commands

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