Here are the essential concepts you must grasp in order to answer the question correctly.
Unit Circle
The unit circle is a circle with a radius of one centered at the origin of a coordinate plane. It is fundamental in trigonometry as it provides a geometric representation of the sine, cosine, and tangent functions. The angles measured in radians correspond to points on the circle, allowing for the determination of exact function values for various angles.
Recommended video:
Introduction to the Unit Circle
Reference Angles
A reference angle is the acute angle formed by the terminal side of a given angle and the x-axis. For angles in standard position, reference angles help simplify the calculation of trigonometric functions by relating them to angles within the first quadrant, where the values of sine and cosine are easier to determine.
Recommended video:
Reference Angles on the Unit Circle
Sine Function
The sine function, denoted as sin(θ), represents the ratio of the length of the opposite side to the hypotenuse in a right triangle. On the unit circle, it corresponds to the y-coordinate of a point at a given angle θ. Understanding the sine function is crucial for finding exact values, especially for angles that are not standard, such as negative angles or those greater than 2π.
Recommended video:
Graph of Sine and Cosine Function