Name
cos
Synopsis
Calculates the cosine of an angle
#include <math.h> doublecos
( doublex
); doublecosf
( floatx
); (C99) doublecosl
( long doublex
); (C99)
The cos()
function returns
the cosine of its argument, which is an angle measure in radians.
The return value is in the range -1 ≤ cos(
x
)
≤ 1.
Example
/* * Calculate the sloping width of a roof * given the horizontal width * and the angle from the horizontal. */ #define PI 3.141593 #define DEG_PER_RAD (180.0/PI) double roof_pitch = 20.0; // In degrees double floor_width = 30.0; // In feet, say. double roof_width = 1.0 / cos( roof_pitch / DEG_PER_RAD ) * floor_width; printf( "The sloping width of the roof is %4.2f ft.\n", roof_width );
This code produces the following output:
The sloping width of the roof is 31.93 ft.
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