Glossary Checklist FAQ
The primary trigonometric ratios, sine, cosine, and tangent, are not new concepts to Math 20-1. It is important to have a good understanding of how to use these ratios with right triangles. As you proceed through Unit 4, you will learn to apply these trigonometric ratios to any angle in any quadrant. This lesson will start with a review of the primary trigonometric ratios, followed by instruction on using reference angles to determine trigonometric ratios for any angle.

In Lesson 4.2, you will

  • use the Pythagorean Theorem to determine the distance from the origin to a point on the terminal arm of an angle in standard position,
  • determine sin \(\theta\), cos \(\theta\), and tan \(\theta\) for any point on the terminal arm of an angle in standard position, \(\theta\), including exact values for reference angles of \(30^\circ\), \(45^\circ\), and \(60^\circ\),
  • determine the sign of a trigonometric ratio for a given angle,
  • solve for \(\theta\), given sin \(\theta = a\), cos \(\theta = a\), tan \(\theta = a\),
  • describe patterns in trigonometric ratios,
  • sketch diagrams for problems involving trigonometric ratios, and
  • solve problems involving trigonometric ratios.