# How do you determine the two coterminal angle (one positive one negative) for the angle -420^circ?

There are a countably infinite number of angles coterminal to -420^circ; we're free to add or subtract ${360}^{\circ}$ as many times as we like to come up with them. Adding once gives our negative answer, $- {60}^{\circ}$ and once more our positive answer, ${300}^{\circ} .$