Find The Exact Value Of $\sin \frac{7 \pi}{2}$.

by ADMIN 48 views

Introduction

In trigonometry, the sine function is a fundamental concept that plays a crucial role in solving various mathematical problems. The sine function is defined as the ratio of the length of the side opposite a given angle to the length of the hypotenuse in a right-angled triangle. However, when dealing with angles in radians, it becomes essential to understand how to evaluate the sine function for such angles. In this article, we will focus on finding the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2}.

Understanding the Angle

To begin with, let's understand the angle 7Ο€2\frac{7 \pi}{2}. This angle is in radians, and we can convert it to degrees to make it easier to visualize. We know that Ο€\pi radians is equivalent to 180∘180^\circ. Therefore, 7Ο€2\frac{7 \pi}{2} radians can be converted to degrees as follows:

7Ο€2Β radians=7Ο€2Γ—180βˆ˜Ο€=630∘\frac{7 \pi}{2} \text{ radians} = \frac{7 \pi}{2} \times \frac{180^\circ}{\pi} = 630^\circ

Evaluating the Sine Function

Now that we have understood the angle, let's evaluate the sine function for 7Ο€2\frac{7 \pi}{2} radians. We know that the sine function has a periodicity of 2Ο€2 \pi, which means that the value of the sine function repeats every 2Ο€2 \pi radians. Therefore, we can rewrite 7Ο€2\frac{7 \pi}{2} as follows:

7Ο€2=2Ο€+Ο€2\frac{7 \pi}{2} = 2 \pi + \frac{\pi}{2}

Using the Periodicity of the Sine Function

Since the sine function has a periodicity of 2Ο€2 \pi, we can use this property to simplify the evaluation of the sine function for 7Ο€2\frac{7 \pi}{2} radians. We know that the sine function is periodic with a period of 2Ο€2 \pi, which means that:

sin⁑(2Ο€+ΞΈ)=sin⁑θ\sin (2 \pi + \theta) = \sin \theta

Therefore, we can rewrite the sine function for 7Ο€2\frac{7 \pi}{2} radians as follows:

sin⁑7Ο€2=sin⁑(2Ο€+Ο€2)=sin⁑π2\sin \frac{7 \pi}{2} = \sin (2 \pi + \frac{\pi}{2}) = \sin \frac{\pi}{2}

Evaluating the Sine Function for Ο€2\frac{\pi}{2}

Now that we have simplified the evaluation of the sine function for 7Ο€2\frac{7 \pi}{2} radians, let's evaluate the sine function for Ο€2\frac{\pi}{2}. We know that the sine function is defined as the ratio of the length of the side opposite a given angle to the length of the hypotenuse in a right-angled triangle. For the angle Ο€2\frac{\pi}{2}, we have a right-angled triangle with a hypotenuse of length 1 and an opposite side of length 1. Therefore, the sine function for Ο€2\frac{\pi}{2} is:

sin⁑π2=11=1\sin \frac{\pi}{2} = \frac{1}{1} = 1

Conclusion

In conclusion, we have found the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2} by using the periodicity of the sine function and evaluating the sine function for Ο€2\frac{\pi}{2}. We have shown that sin⁑7Ο€2=sin⁑(2Ο€+Ο€2)=sin⁑π2=1\sin \frac{7 \pi}{2} = \sin (2 \pi + \frac{\pi}{2}) = \sin \frac{\pi}{2} = 1. This result demonstrates the importance of understanding the properties of the sine function and how to apply them to evaluate trigonometric expressions.

Additional Examples

Here are some additional examples of finding the exact value of the sine function for various angles in radians:

  • sin⁑3Ο€2=sin⁑(2Ο€βˆ’Ο€2)=βˆ’sin⁑π2=βˆ’1\sin \frac{3 \pi}{2} = \sin (2 \pi - \frac{\pi}{2}) = -\sin \frac{\pi}{2} = -1
  • sin⁑5Ο€2=sin⁑(2Ο€+Ο€2)=sin⁑π2=1\sin \frac{5 \pi}{2} = \sin (2 \pi + \frac{\pi}{2}) = \sin \frac{\pi}{2} = 1
  • sin⁑9Ο€2=sin⁑(2Ο€+3Ο€2)=sin⁑3Ο€2=βˆ’1\sin \frac{9 \pi}{2} = \sin (2 \pi + \frac{3 \pi}{2}) = \sin \frac{3 \pi}{2} = -1

These examples demonstrate the importance of understanding the periodicity of the sine function and how to apply it to evaluate trigonometric expressions.

Final Thoughts

In conclusion, finding the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2} requires a deep understanding of the properties of the sine function and how to apply them to evaluate trigonometric expressions. By using the periodicity of the sine function and evaluating the sine function for Ο€2\frac{\pi}{2}, we have shown that sin⁑7Ο€2=1\sin \frac{7 \pi}{2} = 1. This result demonstrates the importance of understanding the properties of the sine function and how to apply them to evaluate trigonometric expressions.

Introduction

In our previous article, we discussed how to find the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2}. We used the periodicity of the sine function and evaluated the sine function for Ο€2\frac{\pi}{2} to arrive at the result. In this article, we will provide a Q&A section to help clarify any doubts and provide additional insights into finding the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2}.

Q: What is the periodicity of the sine function?

A: The sine function has a periodicity of 2Ο€2 \pi, which means that the value of the sine function repeats every 2Ο€2 \pi radians.

Q: How can we use the periodicity of the sine function to simplify the evaluation of the sine function for 7Ο€2\frac{7 \pi}{2}?

A: We can rewrite 7Ο€2\frac{7 \pi}{2} as 2Ο€+Ο€22 \pi + \frac{\pi}{2} and use the periodicity of the sine function to simplify the evaluation of the sine function. This allows us to rewrite the sine function for 7Ο€2\frac{7 \pi}{2} as sin⁑(2Ο€+Ο€2)=sin⁑π2\sin (2 \pi + \frac{\pi}{2}) = \sin \frac{\pi}{2}.

Q: What is the value of the sine function for Ο€2\frac{\pi}{2}?

A: The value of the sine function for Ο€2\frac{\pi}{2} is 1.

Q: How can we use the result of sin⁑π2=1\sin \frac{\pi}{2} = 1 to find the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2}?

A: We can use the result of sin⁑π2=1\sin \frac{\pi}{2} = 1 to find the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2} by substituting sin⁑π2\sin \frac{\pi}{2} into the expression sin⁑(2Ο€+Ο€2)\sin (2 \pi + \frac{\pi}{2}). This gives us sin⁑7Ο€2=sin⁑(2Ο€+Ο€2)=sin⁑π2=1\sin \frac{7 \pi}{2} = \sin (2 \pi + \frac{\pi}{2}) = \sin \frac{\pi}{2} = 1.

Q: What are some additional examples of finding the exact value of the sine function for various angles in radians?

A: Here are some additional examples:

  • sin⁑3Ο€2=sin⁑(2Ο€βˆ’Ο€2)=βˆ’sin⁑π2=βˆ’1\sin \frac{3 \pi}{2} = \sin (2 \pi - \frac{\pi}{2}) = -\sin \frac{\pi}{2} = -1
  • sin⁑5Ο€2=sin⁑(2Ο€+Ο€2)=sin⁑π2=1\sin \frac{5 \pi}{2} = \sin (2 \pi + \frac{\pi}{2}) = \sin \frac{\pi}{2} = 1
  • sin⁑9Ο€2=sin⁑(2Ο€+3Ο€2)=sin⁑3Ο€2=βˆ’1\sin \frac{9 \pi}{2} = \sin (2 \pi + \frac{3 \pi}{2}) = \sin \frac{3 \pi}{2} = -1

Q: How can we use the periodicity of the sine function to find the exact value of sin⁑3Ο€2\sin \frac{3 \pi}{2}?

A: We can rewrite 3Ο€2\frac{3 \pi}{2} as 2Ο€βˆ’Ο€22 \pi - \frac{\pi}{2} and use the periodicity of the sine function to simplify the evaluation of the sine function. This allows us to rewrite the sine function for 3Ο€2\frac{3 \pi}{2} as sin⁑(2Ο€βˆ’Ο€2)=βˆ’sin⁑π2=βˆ’1\sin (2 \pi - \frac{\pi}{2}) = -\sin \frac{\pi}{2} = -1.

Q: What is the final answer to the problem of finding the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2}?

A: The final answer to the problem of finding the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2} is 1.

Conclusion

In conclusion, finding the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2} requires a deep understanding of the properties of the sine function and how to apply them to evaluate trigonometric expressions. By using the periodicity of the sine function and evaluating the sine function for Ο€2\frac{\pi}{2}, we have shown that sin⁑7Ο€2=1\sin \frac{7 \pi}{2} = 1. This result demonstrates the importance of understanding the properties of the sine function and how to apply them to evaluate trigonometric expressions.

Final Thoughts

In conclusion, finding the exact value of sin⁑7Ο€2\sin \frac{7 \pi}{2} is a challenging problem that requires a deep understanding of the properties of the sine function and how to apply them to evaluate trigonometric expressions. By using the periodicity of the sine function and evaluating the sine function for Ο€2\frac{\pi}{2}, we have shown that sin⁑7Ο€2=1\sin \frac{7 \pi}{2} = 1. This result demonstrates the importance of understanding the properties of the sine function and how to apply them to evaluate trigonometric expressions.