What is wrong in the statement: "Function void helper (int X, double T); has time complexity O(N)"

Consider the following recursive function:   void recurse(int num) {   if (num == 0)     cout << “ Zero” << endl;   else {     cout << " " << num << " " << endl;     recurse(num + 1)   } }       Is recurse (-2) a valid call? If a valid call, what is the output of the entire function execution? If not a valid call, explain why it is not a valid call.

Why am I getting errors?  Says "Index 0 out of bounds for length 0" I didn't specify when I asked this question last time, the program needs: write a program that takes two double command line arguments representing the sides of a rectangle. The program should then call a void function that reports the area of the rectangle accurate to three decimal places public static void main(String[] args) {        System.out.println("Enter length and width of rectangle");                for (int i=0; i < args.length; i++)        {            System.out.println(args[i]);        }                        Double area= Double.parseDouble (args[0]) * Double.parseDouble (args[1]);        System.out.println(" Area of rectangle is :" + String.format("%.3f", area));    } }

please help me with the loop for trapezoidal method, and how to modularize the functions needed in the program. my code seem to not be applicable for non-zero lower limits. i am lost. #include #include #include using namespace std; // input lower limit A and upper limit B // input number of trapezoids int main() { double a, b, num, givenEq, midEq, width; cout << "Input lower limit (a): "; cin >> a; cout << "Input upper limit (b): "; cin >> b; cout << "Input number of trapezoids: "; cin >> num; width = (b - a) / num; cout<