Final answer:
The correct answer is option c. To find the exact values of trigonometric functions, use trigonometric identities, which relate the angles and sides of right triangles. The Pythagorean theorem can also be used to find the relationships between the sides of right triangles.
Step-by-step explanation:
Finding the exact values of trigonometric functions can be done using various methods, depending on the information you have and the context of the problem. With a right triangle, you can use the Pythagorean theorem to link the lengths of the legs with the hypotenuse. The theorem states that if you have legs of lengths a and b, and hypotenuse c, the relationship is a² + b² = c², which can be solved for c as c = √(a² + b²).
Moreover, trigonometric identities such as sine, cosine, and tangent functions relate the lengths of the sides of right triangles to the angles. For example, given an angle θ, you can find the cosine of that angle using the adjacent side over the hypotenuse. You can also use these identities to find exact values for special angles, such as 0°, 30°, 45°, 60°, and 90° without a calculator.
The correct option to accurately find the exact values of trigonometric functions is to use trigonometric identities.