double tan(
num x
)

Converts x to a double and returns the tangent of the value.

The tangent function is equivalent to sin(x)/cos(x) and may be infinite (positive or negative) when cos(x) is equal to zero. If x is not a finite number, the result is NaN.

Source

/**
 * Converts [x] to a double and returns the tangent of the value.
 *
 * The tangent function is equivalent to [:sin(x)/cos(x):] and may be
 * infinite (positive or negative) when [:cos(x):] is equal to zero.
 * If [x] is not a finite number, the result is NaN.
 */
external double tan(num x);