Math 20-1 Lesson 4: Trigonometric Ratios of Any Angle (Part 1)
In Lesson 4 of our Trigonometry unit, we learn how to determine the trigonometric ratios of any angle on the coordinate plane. Trigonometric ratios are no longer limited to right triangles — they can be applied to angles in all four quadrants. In this lesson, you’ll learn how to: • Find sine, cosine, and tangent values • Work with angles in all four quadrants • Determine the signs of trig ratios • Use coordinates to calculate trig ratios • Understand the CAST rule This lesson builds the foundation for unit circle trigonometry and solving more advanced trig problems. Perfect for: ✔ Math 20-1 students ✔ Trigonometry unit review ✔ Test preparation ✔ Diploma exam prep
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