Formulas and Functions

Chapter 12 Trigonometric Functions 333
COS
The COS function returns the cosine of an angle that is expressed in radians.
COS(radian-angle)
 radian-angle: An angle, expressed in radians. radian-angle is a number value.
Although it can be any value, it would normally be in the range –π to +π (–pi to +pi).
Usage Notes
To return an angle in degrees, use the DEGREES function (to convert radians to Â
degrees) with this function; that is, =DEGREES(COS(radian-angle)).
Examples
=COS(1) returns 0.540302306, the cosine of 1 radian (approximately 57.3 degrees).
=COS(RADIANS(60)) returns 0.5, the cosine of 60 degrees.
=COS(PI()/3) returns 0.5, π/3 radians (60 degrees).
=COS(PI()) returns –1, the cosine of π radians (180 degrees).
Related Topics
For related functions and additional information, see:
“ACOS” on page 327
“ACOSH” on page 328
“COSH” on page 334
“DEGREES” on page 334
“SIN” on page 336
“TAN” on page 338
“Listing of Trigonometric Functions” on page 326
“Value Types” on page 36
“The Elements of Formulas” on page 15
“Using the Keyboard and Mouse to Create and Edit Formulas” on page 26
“Pasting from Examples in Help” on page 41