Вариант 2. Таск 2

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

int main() {
    double a, b, c, status = scanf("%lf%lf%lf", &a, &b, &c) == 3 && a < b && (b - a) / c == (int)((b - a) / c);

    for (double x = a; x <= b && status; x += c) {
        printf("%lf | ", x);
        if (x <= -1)
            printf("%lf", (pow(x, 3) + 1) * sin(M_PI * x));
        else if (x <= 1)
            printf("%lf", x + 1);
        else
            printf("%lf", exp(x - 1) * cos(x - 1) + 2);

        printf("\n");
    }

    if (!status) printf("n/a");

    return 0;
}