What is represented by the symbol "hi" in optical equations?

The symbol "hi" in optical equations specifically represents the height of the image. This is a critical concept in optics, as understanding the dimensions of an image produced by a lens or mirror is essential for analyzing optical systems. When studying lenses or mirrors, both the image height and object height are important for determining the scale and orientation of images.

In the context of image formation by lenses, knowing the height of the image allows one to calculate attributes like magnification, which compares the image height to the object height. By understanding how "hi" denotes the height of the image in these equations, students can better grasp how images are produced and manipulated in various optical devices.