Untitled

#include<stdio.h>
#include<math.h>

void add();
void subtract();
void multiply();
void divide();
void power();
void square_root();
void factorial();
void sine();
void cosine();
void tangent();

int main() {
    int choice;
    do {
        printf("\nScientific Calculator:\n");
        printf("1. Addition\n");
        printf("2. Subtraction\n");
        printf("3. Multiplication\n");
        printf("4. Division\n");
        printf("5. Power\n");
        printf("6. Square Root\n");
        printf("7. Sine\n");
        printf("8. Cosine\n");
        printf("9. Tangent\n");
        printf("10. Exit\n");
        printf("Choose any one operation: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1: add(); break;
            case 2: subtract(); break;
            case 3: multiply(); break;
            case 4: divide(); break;
            case 5: power(); break;
            case 6: square_root(); break;
            case 7: sine(); break;
            case 8: cosine(); break;
            case 9: tangent(); break;
            case 10: printf("Exiting.\n"); break;
            default: printf("Invalid choice.\n");
        }
    } while (choice!=11);
    return 0;
}
void add() {
    double a, b;
    printf("Enter two no: ");
    scanf("%lf %lf",&a,&b);
    printf("Result: %.2lf\n",a+b);
}
void subtract() {
    double a,b;
    printf("Enter two no: ");
    scanf("%lf %lf",&a,&b);
    printf("Result: %.2lf\n",a-b);
}

void multiply() {
    double a,b;
    printf("Enter two no: ");
    scanf("%lf %lf",&a,&b);
    printf("Result: %.2lf\n",a*b);
}
void divide() {
    double a,b;
    printf("Enter two no: ");
    scanf("%lf %lf",&a,&b);
    if (b!=0)
        printf("Result: %.2lf\n",a/b);
    else
        printf("Error!\n");
}

void power() {
    double base, exp;
    printf("Enter base & exponent: ");
    scanf("%lf %lf", &base, &exp);
    printf("Result: %.2lf\n", pow(base,exp));
}

void square_root() {
    double num;
    printf("Enter a number: ");
    scanf("%lf", &num);
    if (num >= 0)
        printf("Result: %.2lf\n", sqrt(num));
    else
        printf("Error! negative number.\n");
}
void sine() {
    double angle;
    printf("Enter an angle in degrees: ");
    scanf("%lf",&angle);
    double radians=angle*(M_PI/180.0);
    printf("sin(%.2lf)=%.2lf\n", angle, sin(radians));
}

void cosine() {
    double angle;
    printf("Enter an angle in degrees: ");
    scanf("%lf",&angle);
    double radians=angle*(M_PI/180.0);
    printf("cos(%.2lf)=%.2lf\n",angle,cos(radians));
}

void tangent() {
    double angle;
    printf("Enter an angle in degrees: ");
    scanf("%lf",&angle);
    double radians=angle*(M_PI/180.0);
    if ((int)angle%180==90)
        printf("tan(%.2lf) is undefined.\n",angle);
    else
        printf("tan(%.2lf)=%.2lf\n",angle,tan(radians));
}