QUESTION 2If Cos ⁡ Β = Ρ 5 \cos \beta = \frac{\rho}{\sqrt{5}} Cos Β = 5 ​ Ρ ​ Where Ρ \textgreater 0 \rho \ \textgreater \ 0 Ρ \textgreater 0 And $\beta \in [180^{\circ}, 360^{\circ}], Determine The Following Using A Diagram And Expressions In Terms Of Ρ \rho Ρ :1. $\tan

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Introduction

Trigonometry is a branch of mathematics that deals with the relationships between the sides and angles of triangles. In this article, we will focus on solving trigonometric equations, specifically the equation cosβ=ρ5\cos \beta = \frac{\rho}{\sqrt{5}}, where ρ>0\rho > 0 and β[180,360]\beta \in [180^{\circ}, 360^{\circ}]. We will use a diagram and expressions in terms of ρ\rho to determine the value of tanβ\tan \beta.

Understanding the Problem

The given equation is cosβ=ρ5\cos \beta = \frac{\rho}{\sqrt{5}}. We are asked to find the value of tanβ\tan \beta using a diagram and expressions in terms of ρ\rho. To solve this problem, we need to understand the properties of the cosine function and how it relates to the tangent function.

Recall of Trigonometric Identities

Before we proceed, let's recall some important trigonometric identities:

  • cos2β+sin2β=1\cos^2 \beta + \sin^2 \beta = 1
  • tanβ=sinβcosβ\tan \beta = \frac{\sin \beta}{\cos \beta}

These identities will be useful in solving the given equation.

Solving the Equation

To solve the equation cosβ=ρ5\cos \beta = \frac{\rho}{\sqrt{5}}, we can use the following steps:

  1. Square both sides: Square both sides of the equation to get rid of the square root.
  2. Use the Pythagorean identity: Use the Pythagorean identity cos2β+sin2β=1\cos^2 \beta + \sin^2 \beta = 1 to express sin2β\sin^2 \beta in terms of cos2β\cos^2 \beta.
  3. Solve for sinβ\sin \beta: Solve for sinβ\sin \beta using the expression obtained in step 2.
  4. Find tanβ\tan \beta: Find tanβ\tan \beta using the expression for sinβ\sin \beta and the identity tanβ=sinβcosβ\tan \beta = \frac{\sin \beta}{\cos \beta}.

Let's apply these steps to the given equation.

Step 1: Square both sides

cos2β=(ρ5)2\cos^2 \beta = \left(\frac{\rho}{\sqrt{5}}\right)^2

Step 2: Use the Pythagorean identity

cos2β+sin2β=1\cos^2 \beta + \sin^2 \beta = 1

Substitute the expression for cos2β\cos^2 \beta from step 1:

(ρ5)2+sin2β=1\left(\frac{\rho}{\sqrt{5}}\right)^2 + \sin^2 \beta = 1

Step 3: Solve for sinβ\sin \beta

sin2β=1(ρ5)2\sin^2 \beta = 1 - \left(\frac{\rho}{\sqrt{5}}\right)^2

sin2β=1ρ25\sin^2 \beta = 1 - \frac{\rho^2}{5}

sin2β=5ρ25\sin^2 \beta = \frac{5 - \rho^2}{5}

Take the square root of both sides:

sinβ=±5ρ25\sin \beta = \pm \sqrt{\frac{5 - \rho^2}{5}}

Step 4: Find tanβ\tan \beta

tanβ=sinβcosβ\tan \beta = \frac{\sin \beta}{\cos \beta}

Substitute the expressions for sinβ\sin \beta and cosβ\cos \beta:

tanβ=±5ρ25ρ5\tan \beta = \frac{\pm \sqrt{\frac{5 - \rho^2}{5}}}{\frac{\rho}{\sqrt{5}}}

Simplify the expression:

tanβ=±5ρ255ρ\tan \beta = \pm \sqrt{\frac{5 - \rho^2}{5}} \cdot \frac{\sqrt{5}}{\rho}

tanβ=±5ρ2ρ\tan \beta = \pm \frac{\sqrt{5 - \rho^2}}{\rho}

Conclusion

In this article, we solved the trigonometric equation cosβ=ρ5\cos \beta = \frac{\rho}{\sqrt{5}} using a diagram and expressions in terms of ρ\rho. We used the Pythagorean identity and the definition of the tangent function to find the value of tanβ\tan \beta. The final expression for tanβ\tan \beta is ±5ρ2ρ\pm \frac{\sqrt{5 - \rho^2}}{\rho}.

Diagram

Here is a diagram that illustrates the solution:

+---------------+
|              |
|  cos β = ρ/√5  |
|              |
+---------------+
|  sin β = ±√(5-ρ^2)/5  |
|              |
+---------------+
|  tan β = ±√(5-ρ^2)/ρ  |
|              |
+---------------+

Q&A: Frequently Asked Questions

Q: What is the main goal of solving trigonometric equations? A: The main goal of solving trigonometric equations is to find the value of an unknown angle or expression in terms of known values.

Q: What are some common trigonometric identities used to solve equations? A: Some common trigonometric identities used to solve equations include the Pythagorean identity (cos2β+sin2β=1\cos^2 \beta + \sin^2 \beta = 1), the definition of the tangent function (tanβ=sinβcosβ\tan \beta = \frac{\sin \beta}{\cos \beta}), and the definition of the sine and cosine functions.

Q: How do you solve a trigonometric equation with a square root? A: To solve a trigonometric equation with a square root, you can use the following steps:

  1. Square both sides of the equation to get rid of the square root.
  2. Use the Pythagorean identity to express sin2β\sin^2 \beta in terms of cos2β\cos^2 \beta.
  3. Solve for sinβ\sin \beta using the expression obtained in step 2.
  4. Find tanβ\tan \beta using the expression for sinβ\sin \beta and the definition of the tangent function.

Q: What is the difference between the sine and cosine functions? A: The sine and cosine functions are both trigonometric functions that describe the relationships between the sides and angles of a right triangle. The sine function is defined as the ratio of the length of the opposite side to the length of the hypotenuse, while the cosine function is defined as the ratio of the length of the adjacent side to the length of the hypotenuse.

Q: How do you find the value of tanβ\tan \beta in terms of ρ\rho? A: To find the value of tanβ\tan \beta in terms of ρ\rho, you can use the following steps:

  1. Square both sides of the equation cosβ=ρ5\cos \beta = \frac{\rho}{\sqrt{5}} to get rid of the square root.
  2. Use the Pythagorean identity to express sin2β\sin^2 \beta in terms of cos2β\cos^2 \beta.
  3. Solve for sinβ\sin \beta using the expression obtained in step 2.
  4. Find tanβ\tan \beta using the expression for sinβ\sin \beta and the definition of the tangent function.

Q: What is the final expression for tanβ\tan \beta in terms of ρ\rho? A: The final expression for tanβ\tan \beta in terms of ρ\rho is ±5ρ2ρ\pm \frac{\sqrt{5 - \rho^2}}{\rho}.

Q: Can you provide a diagram that illustrates the solution? A: Yes, here is a diagram that illustrates the solution:

+---------------+
|              |
|  cos β = ρ/√5  |
|              |
+---------------+
|  sin β = ±√(5-ρ^2)/5  |
|              |
+---------------+
|  tan β = ±√(5-ρ^2)/ρ  |
|              |
+---------------+

This diagram shows the relationships between the cosine, sine, and tangent functions, as well as the expression for tanβ\tan \beta in terms of ρ\rho.

Conclusion

In this article, we provided a step-by-step guide to solving trigonometric equations, including the equation cosβ=ρ5\cos \beta = \frac{\rho}{\sqrt{5}}. We also answered some frequently asked questions about trigonometric equations and provided a diagram that illustrates the solution. We hope this article has been helpful in understanding the concepts of trigonometric equations and how to solve them.