Periodicity: Periodicity refers to how trigonometric functions repeat their values after certain intervals. For example, sine has a periodicity of 2π radians or 360 degrees.
Unit Circle: The unit circle is a circle with radius 1 centered at the origin (0,0) on the coordinate plane. It helps visualize trigonometric values based on angle measurements.
Inverse Trigonometric Functions:Inverse trigonometric functions undo trigonometric operations. They allow us to find angles when we know ratios of sides in right triangles.