9 Radians on your calculator
Your calculator can be set to calculate trigonometric functions using the radian measure for angles, instead of degrees, by using the key sequence 
(SETUP) 
(Rad).
When in this mode, the display indicator 
is shown.
Activity 18 Radians on your calculator
In this activity, the angles are measured in radians. Find the values of the following expressions, giving your answers correct to 3 significant figures.
Answer
Remember to set your calculator to work in radians before entering these calculations.
(to 3 significant figures).
.Remember:
can be input to the calculator using 
.
or 0.785 (to 3 significant figures).
Notice from the final example in this activity that where an answer is a simple (possibly fractional) multiple of , the answer is displayed in terms of rather than as a decimal number.