In this C++ tutorial, you will learn how to compute the value of (x*y + z) using fma() function of cmath, with syntax and examples.
C++ fma()
C++ fma(x, y, z) computes and returns the value of (x*y + z).
Syntax
The syntax of C++ fma() is
fma(x, y, z)
where
Parameter | Description |
---|---|
x | A double, float, long double, or integral type value. |
y | A double, float, long double, or integral type value. |
z | A double, float, long double, or integral type value. |
Returns
The return value depends on the type of value passed for parameters x, y and z. The return value of fma() is
- double if the arguments are double.
- float if the arguments are float.
- long double if the arguments are long double.
- Promoted to the higher of the given arguments for integral type arguments.
The synopsis of fma() function is
double fma(double x, double y, double z); float fma(float x, float y, float z); long double fma(long double x, long double y, long double z); Promoted fma(Type1 x, Type2 y, Type z); // for integral type argument values
fma() is a function of cmath library. Include cmath library at the start of program, if using fma() function.
Example
In this example, we read three values from user into x, y and z, and find the value of x*y+z using fma() function.
C++ Program
#include <iostream> #include<cmath> using namespace std; int main() { double x, y, z; cout << "Enter x : "; cin >> x; cout << "Enter y : "; cin >> y; cout << "Enter z : "; cin >> z; double result = fma(x, y, z); cout << "fma(x, y, z) : " << result << endl; }
Output
Enter x : 5 Enter y : 2 Enter z : 3 fma(x, y, z) : 13 Program ended with exit code: 0
Run#2
If any of the arguments is inf, then fma() returns inf.
Enter x : inf Enter y : 10 Enter z : 2 fma(x, y, z) : inf Program ended with exit code: 0
Run#3
If any of the arguments is -inf, then fma() returns -inf.
Enter x : -inf Enter y : 2 Enter z : 3 fma(x, y, z) : -inf Program ended with exit code: 0
Conclusion
In this C++ Tutorial, we learned the syntax of C++ fma(), and how to use this function, with the help of examples.