[Term Entry] C++ Math-functions: isgreaterequal()

* [term entry] C++ math-functions: isgreaterequal()

* Refine isgreaterequal() documentation

Updated the description and notes for clarity and accuracy.

* Update isgreaterequal.md

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Author: CadilheP

content/cpp/concepts/math-functions/terms/isgreaterequal/isgreaterequal.md

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+---
+Title: 'isgreaterequal()'
+Description: 'Determines whether the first floating-point value is greater than or equal to the second, without raising floating-point exceptions.'
+Subjects:
+  - 'Computer Science'
+  - 'Game Development'
+Tags:
+  - 'Functions'
+  - 'Math'
+CatalogContent:
+  - 'learn-c-plus-plus'
+  - 'paths/computer-science'
+---
+
+The **`isgreaterequal()`** [function](https://www.codecademy.com/resources/docs/cpp/functions) compares two arithmetic values and returns `true` only when the first is greater than or equal to the second. It never raises floating-point exceptions and always returns `false` if either argument is `NaN`. The function is available through the `<cmath>` header.
+
+## Syntax
+
+```pseudo
+isgreaterequal(x, y)
+```
+
+**Parameters:**
+
+- `x`, `y`: Floating-point or integer values.
+
+> **Notes:**
+>
+> - The function `isgreaterequal()` is defined with overloads so it works with any mix of arithmetic values.
+> - The built-in operator `>=` for floating-point numbers may raise `FE_INVALID` if one or both of the arguments is `NaN`. The function `isgreaterequal()` is a "quiet" version of operator `>=`.
+
+**Return value:**
+
+The `isgreaterequal()` function returns:
+
+- `true` if `x >= y` and neither argument is `NaN`
+- `false` otherwise, including when either value is `NaN`
+
+## Example
+
+The following example checks whether one number is greater than another, including a comparison involving `NaN`:
+
+```cpp
+#include <iostream>
+#include <cmath>
+
+using namespace std;
+
+int main() {
+  float x = 5.5;
+  int y = 3;
+  double z = nan("1");
+
+  cout << boolalpha;
+  cout << x << " is greater than or equal to " << y << ": " << isgreaterequal(x, y) << endl;
+  cout << y << " is greater than or equal to " << x << ": " << isgreaterequal(y, x) << endl;
+  cout << x << " is greater than or equal to " << z << ": " << isgreaterequal(x, z) << " (NaN comparison)" << endl;
+
+  return 0;
+}
+```
+
+The output for this code is as follows:
+
+```shell
+5.5 is greater than or equal to 3: true
+3 is greater than or equal to 5.5: false
+5.5 is greater than or equal to nan: false (NaN comparison)
+```
+
+## Codebyte Example
+
+The following example is runnable and outputs whether one number is greater than or equal to another using `isgreaterequal()`:
+
+```codebyte/cpp
+#include <iostream>
+#include <cmath>
+using namespace std;
+
+int main() {
+  float a = 2.5;
+  float b = 7.3;
+
+  cout << boolalpha;
+  cout << a << " is greater than or equal to " << b << ": " << isgreaterequal(a, b) << endl;
+  cout << b << " is greater than or equal to " << a << ": " << isgreaterequal(b, a) << endl;
+
+  return 0;
+}
+```