Table of contents
- 0. Review of College Algebra4h 43m
- 1. Measuring Angles40m
- 2. Trigonometric Functions on Right Triangles2h 5m
- 3. Unit Circle1h 19m
- 4. Graphing Trigonometric Functions1h 19m
- 5. Inverse Trigonometric Functions and Basic Trigonometric Equations1h 41m
- 6. Trigonometric Identities and More Equations2h 34m
- 7. Non-Right Triangles1h 38m
- 8. Vectors2h 25m
- 9. Polar Equations2h 5m
- 10. Parametric Equations1h 6m
- 11. Graphing Complex Numbers1h 7m
2. Trigonometric Functions on Right Triangles
Trigonometric Functions on Right Triangles
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
If tanθ=512, find the values of the five other trigonometric functions. Rationalize the denominators if necessary.
A
sinθ=1312,cosθ=135,cotθ=125,secθ=513,cscθ=1213
B
sinθ=135,cosθ=1312,cotθ=125,secθ=1213,cscθ=513
C
sinθ=1312,cosθ=135,cotθ=−125,secθ=−513,cscθ=−1213
D
sinθ=135,cosθ=1312,cotθ=−125,secθ=−1213,cscθ=−513

1
Start by understanding that \( \tan\theta = \frac{12}{5} \) represents the ratio of the opposite side to the adjacent side in a right triangle. This means the opposite side is 12 units and the adjacent side is 5 units.
Use the Pythagorean theorem to find the hypotenuse. The formula is \( c = \sqrt{a^2 + b^2} \), where \( a = 12 \) and \( b = 5 \). Calculate \( c = \sqrt{12^2 + 5^2} \).
Now that you have the hypotenuse, you can find \( \sin\theta \) and \( \cos\theta \). \( \sin\theta = \frac{\text{opposite}}{\text{hypotenuse}} \) and \( \cos\theta = \frac{\text{adjacent}}{\text{hypotenuse}} \). Substitute the values to find \( \sin\theta \) and \( \cos\theta \).
To find \( \cot\theta \), use the reciprocal of \( \tan\theta \). Since \( \tan\theta = \frac{12}{5} \), \( \cot\theta = \frac{5}{12} \).
Finally, find \( \sec\theta \) and \( \csc\theta \) using the reciprocals of \( \cos\theta \) and \( \sin\theta \) respectively. \( \sec\theta = \frac{1}{\cos\theta} \) and \( \csc\theta = \frac{1}{\sin\theta} \). Rationalize the denominators if necessary.
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Open Question
Concept Check Find a solution for each equation. sin(4θ + 2°) csc(3θ + 5°) = 1
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Trigonometric Functions on Right Triangles practice set
