<h2>Overview</h2>

The **`fmaxf()`** function in C is defined in the `<math.h>` header file. `fmaxf()` takes two arguments (`x` and `y`) of type float as input and returns the larger of the two numbers. The function is defined in the `<math.h>` header file as:

```C
float fmaxf( float x, float y );
```

<h2>Examples</h2>

Below is an example of how to use `fmaxf()`. Using an example of $x = 3.3$ and $y = 2.7$, we use the `fmaxf()` function to print the largest floating-point number. 

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

int main() {
    float largest = fmaxf(3.3, 2.7);

    printf("The larger of the two numbers is: %f\n", largest);
    return 0;
}

Below are the ways in which the results of the `fmaxf()` function vary for different values of `x` and `y`:

1. If `x` is `Not a Number (NaN)`, `fmaxf()` will return `y`, and vice versa

2. If both inputs are `NaN`, the return value is also `NaN`

The code below demonstrates these input values and their results:

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

int main() {
    printf("The larger of the two numbers if one is NAN is: %f\n", fmaxf(NAN, 2.7));

    printf("The larger of the two numbers if both are NAN is: %f\n", fmaxf(NAN, NAN));

    return 0;
}

What is fmaxf in C?

The fmaxf() function in C returns the larger of two float values, defined in <math.h>.