2. standard functions)
C
header file C h
header file
include<header file.h>
C compiler
library functions)

3. pow(x,y)
xy x y
double pow(x,y)
header file math.h
include<math.h>
main
pow(x,y)

4. mathematic functions)
include <math.h>
type) double
double
acos(x) asin(x) atan(x)
sin(x) cos(x) tan(x)
sqrt(x) exp(x) pow(x,y)
log(x) log (x) ceil(x)
floor(x) fabs(x)

5. acos(x)
arc cosine x x
radian) acos(x);
asin(x)
arc sine x x
asin(x);
atan(x)
arc tan x x
atan(x);
sin(x)
sine x x
sin(x);
cos(x)
cosine x x
cos(x);
tan(x)
tan x x
tan(x);

6. acos(x),
asin(x), atan(x), sin(x), cos(x) tan(x)
/* math1.c */
#include<stdio.h> /*
include<math.h> /*
include<conio.h> /*
void main(void) /*
double r, pi = 3.141592654; /*
r = pi/180; /*
clrscr(); /*
printf("%fn",asin(r)); /*
printf("%fn",acos(r)); /*
printf("%fn",atan(r)); /*
printf("%fn",sin(r)); /*
printf("%fn",cos(r)); /*
printf("%fn",tan(r)); /*
printf("nPress any key back to program ..."); /*
getch(); /*

8. printf("%fn",asin(r));
arc sin r r
printf("%fn",acos(r));
arc cosine r r
printf("%fn",atan(r));
arc tan r r
printf("%fn",sin(r));
sine r r

9. printf("%fn",cos(r));
cosine r r
printf("%fn",tan(r));
tan r r
enter

10. sqrt(x)
square root)
x x
sqrt(x);
exp(x)
ex x
e e
exp(x);
pow(x,y)
xy
pow(x, y);

11. sqrt(x), exp(x) pow(x, y)
/* math2.c */
#include<stdio.h> /*
include<math.h> /*
include<conio.h> /*
void
main(void) /*
double x = 2.5, y = 7.0, z = 21.5; /*
clrscr( ); /*
printf("%.4fn",pow(x,y)); /*
printf("%.4fn",sqrt(z)); /*
printf("%.4fn",exp(y)); /*

13. printf("%.4fn",pow(x,y));
xy x
y
printf("%.4fn",sqrt(z));
square root)
z z
printf("%.4fn",exp(y));
ey y
e e

14. log(x)
log n (natural
logarithm) x x
log(x);
log10(x)
log
x x
log10(x);
ceil(x)
x x x
ceil(x);

15. floor(x)
x x x
floor(x);
fabs(x)
absolute value)
x x
fabs(x);

16. clrscr( )
text mode
clrscr( );
gotoxy(x,y)
cursor)
gotoxy(x,y );
clreol( )
cursor
cursor
clreol( );

17. deline( )
cursor
deline( );
insline( )
cursor
insline( );
sizeof(x)
x
Byte
sizeof(x);
system( ) sizeof(type);
MS-DOS
system(“dos-command”);

18. abort( )
Abnormal program termination”
abort( );
abs(x)
x x
abs(x);
atoi( ) char numstr[20] = “1000”; int d;d =atoi(numstr);
printf (“%d”, d);

19. atoi( ), atof(
) atol( )
/* atoifl.c */
#include<stdio.h> /*
include<stdlib.h> /*
include<conio.h> /*
void main(void) /*
char s1[5] = "123"; /*
char s2[10] = "14.573"; /*
char s3[15] = "1234567891"; /*
int as1; float fs2; long ls3; /*
clrscr( ); /*
as1 = 2 * atoi(s1); /*
fs2 = 2 * atof(s2); /*
ls3 = atol(s3); /*
printf("AS1 = %dn",as1); /*
printf("FS2 = %fn",fs2); /*
printf("LS3 = %ldn",ls3); /*
printf("nPress any key back to program ..."); /*
getch(); /*

21. atoi( ) s1
as1
atof( ) s2
fs2
atol( ) s3
long integer
ls3
as1, fs2 as3

22. 15
18
19