How do you use a calculator to evaluate #cos((8pi)/7)#?

2 Answers
May 17, 2018

See process


In Casio calculators

Be sure to set calculator in RAD mode (important)

Press "cos" key and then introduce #(8xxpi)/7#

Press "=" and you got it

In others trade marks read the user guide (trigonometric functions) to follow equivalent steps to prior process

May 18, 2018

Set calculator on "Deg."
On the calculator, transform ((8pi)/7)) to degrees -->
#(8(180))/7 = 205.7142857#.
Press "cos", get: #- 0.90#