This document discusses trigonometric identities and relationships between trigonometric functions. It covers the Pythagorean identity that the sum of the squares of the sine and cosine of an angle is 1, the definition of the tangent of an angle as the ratio of the sine to the cosine, and expressions for r in terms of other trigonometric functions in polar coordinate systems.

7. cos2 𝜃 + sin2 𝜃 = 1
𝑡𝑎𝑛𝜃 =
sin 𝜃
cos 𝜃

12. 𝜽 = 𝜷

13. 𝑎
𝒃
𝜃

15. 𝑟 = 𝑎
𝑎

23. 𝑟 = cos(3𝜃)

24. 𝑟 = cos(3𝜃)

25. 𝑟 = cos(2𝜃)

26. 𝑟 =
1
1 + 𝑐𝑜𝑠𝜃

27. 𝑟 =
1
1 + 𝑐𝑜𝑠𝜃

28.  https://tutorial.math.lamar.edu/Problems/CalcII/PolarCoordinates.aspx