Page 18 - PROGRAMMING IN C_Neat

10. Explain union with an example. *

Union:
 Union is like a structure but all its members share the same memory area.
 The size of a union variable is the size of its largest member.
 General Form:
union union_name
{
datatype1 member1;

datatype2 member2;
_

_
_
datatype n member n;
};

union union_name variable_name;

 Example:
union student
{
int rollno;
char name[20];
float percentage;
};

union student s;

 The members of the union can be accessed as follows:
s.rollno
s.name
s.percentage
 The largest member of the union is name (20 characters). Its size is 20 bytes. Therefore, the size of the
union variable, s is 20 bytes.
_______________________________________________________________________________________

11. Explain the important functions available in <math.h> header file. OR Explain the math
functions. *

Math Functions:
 Mathematical functions are stored in the math.h header file.

1. sin():
 Used to find the sin value of its argument.
 General Form:

double sin(double a);

 Example:
double x = sin(3.14/2); Output:
x = 1 (approx.)

2. cos():
 Used to find the cos value of its argument.