C math.h Library Reference

1#include <stdio.h>
2#include <math.h>
3
4int main() {
5    // Power
6    printf("2^10 = %.0f\n", pow(2, 10));      // 1024
7    printf("5^3 = %.0f\n", pow(5, 3));        // 125
8    
9    // Square root
10    printf("√16 = %.0f\n", sqrt(16));         // 4
11    printf("√2 = %.4f\n", sqrt(2));           // 1.4142
12    
13    // Cube root
14    printf("∛27 = %.0f\n", cbrt(27));         // 3
15    
16    // Hypotenuse (Pythagorean theorem)
17    printf("hypot(3,4) = %.0f\n", hypot(3, 4)); // 5
18    
19    return 0;
20}

1#include <stdio.h>
2#include <math.h>
3
4#define PI 3.14159265358979323846
5
6int main() {
7    // Convert degrees to radians
8    double deg = 45.0;
9    double rad = deg * (PI / 180.0);
10    
11    printf("sin(45°) = %.4f\n", sin(rad));  // 0.7071
12    printf("cos(45°) = %.4f\n", cos(rad));  // 0.7071
13    printf("tan(45°) = %.4f\n", tan(rad));  // 1.0000
14    
15    // Inverse trig (returns radians)
16    double angle = asin(0.5);  // 30° in radians
17    printf("asin(0.5) = %.4f rad = %.1f°\n", 
18           angle, angle * (180.0 / PI));
19    
20    // Use M_PI constant (if available)
21    printf("sin(π/2) = %.4f\n", sin(M_PI / 2));  // 1.0000
22    
23    return 0;
24}

1#include <stdio.h>
2#include <math.h>
3
4int main() {
5    // Exponential
6    printf("e^1 = %.4f\n", exp(1));     // 2.7183
7    printf("e^2 = %.4f\n", exp(2));     // 7.3891
8    
9    // Natural logarithm (base e)
10    printf("ln(e) = %.4f\n", log(M_E)); // 1.0000
11    printf("ln(10) = %.4f\n", log(10)); // 2.3026
12    
13    // Base-10 logarithm
14    printf("log10(100) = %.4f\n", log10(100));  // 2.0000
15    printf("log10(1000) = %.4f\n", log10(1000)); // 3.0000
16    
17    // Base-2 logarithm
18    printf("log2(8) = %.4f\n", log2(8));   // 3.0000
19    printf("log2(1024) = %.4f\n", log2(1024)); // 10.0000
20    
21    return 0;
22}

1#include <stdio.h>
2#include <math.h>
3
4int main() {
5    double x = 3.7, y = -3.7;
6    
7    printf("Value    ceil   floor  round  trunc\n");
8    printf("%.1f     %.0f     %.0f     %.0f     %.0f\n", 
9           x, ceil(x), floor(x), round(x), trunc(x));
10    printf("%.1f    %.0f    %.0f    %.0f    %.0f\n", 
11           y, ceil(y), floor(y), round(y), trunc(y));
12    
13    // Output:
14    // Value    ceil   floor  round  trunc
15    // 3.7      4      3      4      3
16    // -3.7    -3     -4     -4     -3
17    
18    return 0;
19}

1#include <stdio.h>
2#include <math.h>
3
4int main() {
5    // Absolute value
6    printf("fabs(-5.5) = %.1f\n", fabs(-5.5));  // 5.5
7    
8    // Floating-point modulo
9    printf("fmod(5.3, 2) = %.1f\n", fmod(5.3, 2));  // 1.3
10    
11    // Max and Min
12    printf("fmax(3.5, 2.1) = %.1f\n", fmax(3.5, 2.1));  // 3.5
13    printf("fmin(3.5, 2.1) = %.1f\n", fmin(3.5, 2.1));  // 2.1
14    
15    return 0;
16}