MATHEMATICS: Mathematical Programming in C | FYUG 2025

Question: Write the syntax for variable declaration in C.

Solution:

data_type variable_name;

Example: int count; or float price;

Question: Write the syntax to define a symbolic constant.

Solution:

#define CONSTANT_NAME value

Example: #define PI 3.14159

Question: How will you write the arithmetic expression a² + 10a - 8 in C?

Solution:

a * a + 10 * a - 8;

Alternatively, using the math library: pow(a, 2) + 10 * a - 8;

Question: How will you assign the value 100 to the variable x at the time of variable declaration?

Solution:

int x = 100;

Question: Which of the following are valid variable names: Char, First_name, List one, 2int_type?

Solution:

• Char: Valid (C is case-sensitive; char is a keyword, but Char is not).
• First_name: Valid (contains letters and underscores).
• List one: Invalid (contains a space).
• 2int_type: Invalid (cannot start with a digit).

Question: Write the rules for naming identifiers.

Solution:

1. An identifier can only contain alphabets (uppercase and lowercase), digits, and underscores (_).
2. The first character must be an alphabet or an underscore. It cannot be a digit.
3. Keywords (like int, while, etc.) cannot be used as identifiers.
4. Identifiers are case-sensitive (e.g., Total and total are different).
5. No special characters or spaces are allowed except for the underscore.

Question: What are the relational operators in C?

Solution:

Relational operators are used to compare two values. They are:

• == (Equal to)
• != (Not equal to)
• > (Greater than)
• < (Less than)
• >= (Greater than or equal to)
• <= (Less than or equal to)

Question: What is the error in: int x=10; float y=4.25; x=y%x;?

Solution:

Question: Write a C program to read two integers m and n and to decide and print whether m is a multiple of n.

Solution:

#include 
int main() {
int m, n;
printf("Enter two integers (m and n): ");
scanf("%d %d", &m, &n);
if (n != 0 && m % n == 0) {
    printf("%d is a multiple of %d\n", m, n);
} else {
    printf("%d is not a multiple of %d\n", m, n);
}
return 0;

}

Question: Write the general syntax of for loop.[span_30](end_span)

Solution:

for (initialization; condition; increment/decrement) {
// Statements to be executed
}

Question: Write the rules for switch statement.[span_32](end_span)

Solution:

1. The switch expression must be an integral type (int or char).
2. Each case label must be a unique constant expression.
3. The break statement is optional but used to exit the switch block; otherwise, execution "falls through" to the next case.
4. The default case is optional and executes if no case matches.
5. Case labels must end with a colon (:).

Question: Every program must have a ______ function.[span_39](end_span)

Solution:

main

Question: What is recursion?[span_41](end_span)

Solution:

Question: Write a C program to compute the sum of first n natural numbers using function.[span_45](end_span)

Solution:

#include 
int findSum(int n) {
return (n * (n + 1)) / 2;
}
int main() {
int n;
printf("Enter a positive integer: ");
scanf("%d", &n);
printf("Sum of first %d natural numbers is %d\n", n, findSum(n));
return 0;
}

Question: Write the syntax for declaring a two-dimensional array.

Solution:

data_type array_name[row_size][column_size];

Question: What is the first subscript of one-dimensional array in C?

Solution:

0

Question: Write a program to find the largest element in an integer array.

Solution:

#include 
int main() {
int arr[100], n, i, max;
printf("Enter number of elements: ");
scanf("%d", &n);
printf("Enter %d elements:\n", n);
for(i = 0; i < n; i++) {
    scanf("%d", &arr[i]);
}

max = arr[0];
for(i = 1; i < n; i++) {
    if(arr[i] > max) {
        max = arr[i];
    }
}

printf("Largest element = %d\n", max);
return 0;

}