cos
The trigonometric cosine function.
Syntax
-
cos(x)-
xis a real or complex number
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Description
If x is a real number, cos(x) is the x coordinate of the intersection of the unit circle x^2 + y^2 = 1 and the ray from the origin making an angle x (in radians) from the positive x axis in the anticlockwise direction.
If z is a complex number, cos(z) is defined as [e^(i⋅z) + e^(−i⋅z)]/2.
Notes
If you want to specify the argument in degrees, you can use the ° postfix operator, which amounts to multiplication by π/180.
Examples
cos(0)
1
cos(π/2)
0
cos(180°)
−1
cos(i)
1.54308063482