The small-angle approximations can be used to approximate the values of the main trigonometric functions, provided that the angle in question is small and is measured in radians: {\displaystyle ...

What is meant by a small-angle approximation?

A definition or brief description of Small angle approximation. A mathematical rule that for a small angle expressed in radians, its sine and tangent are approximately equal to the angle.

When can you use small-angle approximation?

When calculating the period of a simple pendulum, the small-angle approximation for sine is used to allow the resulting differential equation to be solved easily by comparison with the differential equation describing simple harmonic motion.