(d)

The expression is often encountered in the context of right triangles, particularly in trigonometry when using the Pythagorean theorem. It represents the hypotenuse when one leg is 1 and the other is . In calculus, this expression frequently appears during integration problems involving trigonometric or hyperbolic functions, creating a connection between algebra and geometric concepts.

In real-world application, this expression shows up in various fields such as physics and engineering, especially when dealing with distance measurements in two-dimensional space. For instance, if an object moves along a path that creates a right triangle with the horizontal and vertical axes, can help calculate the distance from the origin to the object, facilitating more efficient problem solving in navigation and motion analysis.