Therefore, it is useful for mirror design and fabrication in practice.
The idea is that while navigation screens can be useful, a mirror is far less obtrusive and is a place a driver already regularly glances (or should, in theory).
As someone who was in the room as an observer at the Groupon board when the decision to use these metrics was made, I think Groupon was honestly trying to provide additional information that investors would find useful, which mirrored the way management thought about running the business.
Some transit telescopes use a basin of mercury to form a flat and absolutely horizontal mirror, useful in determining an absolute vertical or perpendicular reference.
He clicked open a door to the right of the video console, revealing a lighted makeup mirror — useful upon arrival.
For instance, while one form of some pharmaceutical compounds serves a useful purpose, their mirror images aren't recognized by the body and in some cases can even be harmful.
Each approach provides advantages that are useful in designing mirrors to achieve diffraction limited focusing.
A lighted magnifying mirror is useful for shaving and applying makeup.
They can also be installed as dressing room mirrors, supplying useful information about products without obstructing the customer's view.
These broad mirrors are useful in many research experiments of interferometry and spectroscopy.
