acos()

Returns the arc cosine in the radian measure.

Synopsis

float acos(float x);

Parameter

Parameter Description
x angle

Return Value

Arc cosine in the radian measure. In the event of an error 0.0 is returned.

If the argument is lying outside of the value range [-1..+1], NaN (Not a Number) is returned.

Description

Returns the arc cosine between 0 and pi in the radian measure. x may be from - 1 to 1.

Example

main()
{
  float f;
  f = cos(deg2rad(90));
//results in 0
  f = cosh(0.33);

//results in 1.05495
  f = acos(1);

// results in 0
}

Assignment

Mathematical function

Availability

CTRL

See also

cos(), cosh(),isinf(), isnan()