Understanding Complementary Angles and Trigonometric Ratios

Oct 13, 2025 by wbrum.org 81 views

In Right Triangle XYZ, ∠X and ∠Z are Complementary Angles, and cos(X) = 9/11. What is sin(Z)?

Understanding Complementary Angles and Trigonometric Ratios

In a right-angled triangle, complementary angles are two angles whose sum is 90 degrees. In the given triangle XYZ, ∠X and ∠Z are complementary angles, which means ∠X + ∠Z = 90 degrees. The trigonometric ratios of sine, cosine, and tangent are defined as the ratios of the lengths of the sides of a right-angled triangle. In this case, we are given the value of cos(X) and asked to find the value of sin(Z).

Recalling the Relationship Between Sine and Cosine

The sine and cosine functions are related to each other through the Pythagorean identity: sin^2(X) + cos^2(X) = 1. This identity can be used to find the value of sin(X) if the value of cos(X) is known. However, in this case, we are asked to find the value of sin(Z), not sin(X). To find sin(Z), we need to use the fact that ∠X and ∠Z are complementary angles.

Using the Complementary Angles Property

Since ∠X and ∠Z are complementary angles, we can write ∠Z = 90 - ∠X. Using this relationship, we can find the value of sin(Z) in terms of sin(X). We know that sin(Z) = sin(90 - ∠X) = cos(∠X). Therefore, sin(Z) = cos(X).

Finding the Value of sin(Z)

We are given that cos(X) = 9/11. Since sin(Z) = cos(X), we can conclude that sin(Z) = 9/11.

Conclusion

In the right triangle XYZ, ∠X and ∠Z are complementary angles, and cos(X) = 9/11. Using the relationship between sine and cosine, we found that sin(Z) = cos(X) = 9/11.

Final Answer

The final answer is B.
Q&A: Understanding Complementary Angles and Trigonometric Ratios

Q: What are complementary angles?

A: Complementary angles are two angles whose sum is 90 degrees. In the context of a right-angled triangle, complementary angles are two angles that add up to 90 degrees.

Q: How are sine and cosine related to each other?

A: The sine and cosine functions are related to each other through the Pythagorean identity: sin^2(X) + cos^2(X) = 1. This identity can be used to find the value of sin(X) if the value of cos(X) is known.

Q: What is the relationship between sin(Z) and cos(X)?

A: Since ∠X and ∠Z are complementary angles, we can write ∠Z = 90 - ∠X. Using this relationship, we can find the value of sin(Z) in terms of sin(X). We know that sin(Z) = sin(90 - ∠X) = cos(∠X). Therefore, sin(Z) = cos(X).

Q: How do you find the value of sin(Z) if you know the value of cos(X)?

A: If you know the value of cos(X), you can find the value of sin(Z) by using the relationship sin(Z) = cos(X).

Q: What is the value of sin(Z) if cos(X) = 9/11?

A: Since sin(Z) = cos(X), we can conclude that sin(Z) = 9/11.

Q: What is the significance of the Pythagorean identity in trigonometry?

A: The Pythagorean identity is a fundamental concept in trigonometry that relates the sine and cosine functions. It can be used to find the value of sin(X) if the value of cos(X) is known, and vice versa.

Q: How do you use the Pythagorean identity to find the value of sin(X) if you know the value of cos(X)?

A: To find the value of sin(X) if you know the value of cos(X), you can use the Pythagorean identity: sin^2(X) + cos^2(X) = 1. Rearranging this equation, we get sin^2(X) = 1 - cos^2(X). Taking the square root of both sides, we get sin(X) = ±√(1 - cos^2(X)).

Q: What is the final answer to the problem of finding sin(Z) if cos(X) = 9/11?

A: The final answer is sin(Z) = 9/11.

Q: What is the significance of complementary angles in trigonometry?

A: Complementary angles are an important concept in trigonometry that allows us to relate the sine and cosine functions. They are used to find the value of sin(Z) if the value of cos(X) is known, and vice versa.

Q: How do you use complementary angles to find the value of sin(Z) if you know the value of cos(X)?

A: To find the value of sin(Z) if you know the value of cos(X), you can use the relationship sin(Z) = cos(X). This relationship is based on the fact that ∠X and ∠Z are complementary angles.

Q: What is the final answer to the problem of finding sin(Z) if cos(X) = 9/11?

A: The final answer is sin(Z) = 9/11.