# tan, atan

Tangent and arctangent

## tan

Tangent

tan x    tan[x]


Returns the tangent of x, taken to be in radians. Integer arguments are promoted to floating point. Null is returned if the argument is null or infinity.

q)tan 0 0.5 1 1.5707963 2 0w
0 0.5463025 1.557408 3.732054e+07 -2.18504 0n


The function is atomic, and equivalent to {(sin x)%cos x}.

## atan

Arctangent

atan x    atan[x]


Returns the arctangent of x; that is, the value whose tangent is x. The result is in radians and lies between $-{\pi}{2}$ and ${\pi}{2}$. The range is approximate due to rounding errors.

q)atan 0.5
0.4636476
q)atan 42
1.546991