Find the reference angle for each angle.
5π/4

Key Concepts

Reference Angle

The reference angle is the acute angle formed by the terminal side of a given angle and the x-axis. It is always measured as a positive angle and is used to simplify the calculation of trigonometric functions. For angles greater than 180 degrees, the reference angle is found by subtracting the angle from 180 degrees or 360 degrees, depending on the quadrant in which the angle lies.

Quadrants of the Unit Circle

The unit circle is divided into four quadrants, each representing a range of angles. The first quadrant (0 to π/2) contains angles where both sine and cosine are positive. The second quadrant (π/2 to π) has positive sine and negative cosine, the third quadrant (π to 3π/2) has both sine and cosine negative, and the fourth quadrant (3π/2 to 2π) has positive cosine and negative sine. Understanding these quadrants is essential for determining the reference angle.

Angle Measurement in Radians

Angles can be measured in degrees or radians, with radians being the standard unit in trigonometry. One full rotation (360 degrees) is equivalent to 2π radians. To convert degrees to radians, multiply by π/180. When working with angles like 5π/4, recognizing that this angle is in radians helps in accurately determining its position on the unit circle and subsequently finding the reference angle.