Table of contents
- 0. Fundamental Concepts of Algebra3h 29m
- 1. Equations and Inequalities3h 27m
- 2. Graphs1h 43m
- 3. Functions & Graphs2h 17m
- 4. Polynomial Functions1h 54m
- 5. Rational Functions1h 23m
- 6. Exponential and Logarithmic Functions2h 28m
- 7. Measuring Angles40m
- 8. Trigonometric Functions on Right Triangles2h 5m
- 9. Unit Circle1h 19m
- 10. Graphing Trigonometric Functions1h 19m
- 11. Inverse Trigonometric Functions and Basic Trig Equations1h 41m
- 12. Trigonometric Identities 2h 34m
- 13. Non-Right Triangles1h 38m
- 14. Vectors2h 25m
- 15. Polar Equations2h 5m
- 16. Parametric Equations1h 6m
- 17. Graphing Complex Numbers1h 7m
- 18. Systems of Equations and Matrices3h 6m
- 19. Conic Sections2h 36m
- 20. Sequences, Series & Induction1h 15m
- 21. Combinatorics and Probability1h 45m
- 22. Limits & Continuity1h 49m
- 23. Intro to Derivatives & Area Under the Curve2h 9m
9. Unit Circle
Defining the Unit Circle
Struggling with Precalculus?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Identify the quadrant that the given angle is located in.
47π radians
A
Quadrant I
B
Quadrant II
C
Quadrant III
D
Quadrant IV

1
Convert the given angle from radians to degrees if necessary, but in this case, we will work directly with radians.
Recall that the unit circle is divided into four quadrants, each covering an angle of π/2 radians (or 90 degrees).
Determine the reference angle by finding the equivalent angle between 0 and 2π radians. Since 7π/4 is already between 0 and 2π, we can use it directly.
Identify the quadrant by comparing the angle to the boundaries of each quadrant: Quadrant I (0 to π/2), Quadrant II (π/2 to π), Quadrant III (π to 3π/2), and Quadrant IV (3π/2 to 2π).
Since 7π/4 is greater than 3π/2 and less than 2π, it falls in Quadrant IV.
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