The r Command

radian.png

Command Summary

Converts an angle to radians, if necessary.

Command Syntax

angle r

Menu Location

  • Press 2nd MATH to enter the MATH popup menu.
  • Press 2 to enter the Angle submenu.
  • Press 2 to select r.

Calculator Compatibility

This command works on all calculators.

Token Size

1 byte

NOTE: Due to the limitations of the wiki markup language, the r command on this page does not appear as it would on the calculator. See Wiki Markup Limitations for more information.

The r symbol used after an angle makes sure the angle is interpreted as being in radians. If the calculator is already in radian mode, xr is equal to x; in degree mode, xr is equal to 180*x/π; and in gradian mode, xr is equal to 200*x/π.

If you're using radian angle measures extensively in a program, it's a better idea to use setMode() to switch to radian mode and not worry about this. However, there are two reasons you might want to use r:

  • If you need an angle in radians only once or twice, don't bother changing the mode setting.
  • In a function, you're forced to use r, since setMode() isn't valid in a function.

Make sure to use parentheses around an expression like (π/3)r, since π/3r will be interpreted as π/(3r), and the conversion will be done incorrectly.

In radian mode (no conversion is necessary, so no conversion is done):

:sin(π/6)
           1/2
:sin((π/6)^r)
           1/2
:π^r
           π

In degree mode:

:sin(π/6)
           sin(π/6)
:sin((π/6)^r)
           1/2
:π^r
           180

Related Commands

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