Solve For X X X In The Equation Sin ⁡ ( 2 X ) − Sin ⁡ ( X ) = 0 \sin(2x) - \sin(x) = 0 Sin ( 2 X ) − Sin ( X ) = 0 , Where 0 ≤ X \textless 2 Π 0 \leq X \ \textless \ 2\pi 0 ≤ X \textless 2 Π . What Are The Possible Solutions For X X X ?A. { Π 6 , 5 Π 6 } \left\{\frac{\pi}{6}, \frac{5\pi}{6}\right\} { 6 Π ​ , 6 5 Π ​ } B.

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Introduction

Trigonometric equations are a fundamental concept in mathematics, and solving them requires a deep understanding of trigonometric functions and their properties. In this article, we will focus on solving the equation sin(2x)sin(x)=0\sin(2x) - \sin(x) = 0, where 0x \textless 2π0 \leq x \ \textless \ 2\pi. This equation is a classic example of a trigonometric equation that can be solved using various techniques, including the sum-to-product identity and the double-angle formula.

Understanding the Equation

The given equation is sin(2x)sin(x)=0\sin(2x) - \sin(x) = 0. To solve this equation, we need to find the values of xx that satisfy the equation. The equation involves the sine function, which is a periodic function with a period of 2π2\pi. This means that the sine function repeats its values every 2π2\pi radians.

Using the Sum-to-Product Identity

One of the most useful techniques for solving trigonometric equations is the sum-to-product identity. The sum-to-product identity states that sin(a)sin(b)=2cos(a+b2)sin(ab2)\sin(a) - \sin(b) = 2\cos\left(\frac{a+b}{2}\right)\sin\left(\frac{a-b}{2}\right). We can use this identity to rewrite the given equation as:

sin(2x)sin(x)=2cos(2x+x2)sin(2xx2)\sin(2x) - \sin(x) = 2\cos\left(\frac{2x+x}{2}\right)\sin\left(\frac{2x-x}{2}\right)

Simplifying the expression, we get:

sin(2x)sin(x)=2cos(3x2)sin(x2)\sin(2x) - \sin(x) = 2\cos\left(\frac{3x}{2}\right)\sin\left(\frac{x}{2}\right)

Using the Double-Angle Formula

Another useful technique for solving trigonometric equations is the double-angle formula. The double-angle formula states that sin(2a)=2sin(a)cos(a)\sin(2a) = 2\sin(a)\cos(a). We can use this formula to rewrite the given equation as:

sin(2x)sin(x)=2sin(x)cos(x)sin(x)\sin(2x) - \sin(x) = 2\sin(x)\cos(x) - \sin(x)

Simplifying the expression, we get:

sin(2x)sin(x)=sin(x)(2cos(x)1)\sin(2x) - \sin(x) = \sin(x)(2\cos(x) - 1)

Solving the Equation

Now that we have rewritten the equation using the sum-to-product identity and the double-angle formula, we can solve for xx. Setting the expression equal to zero, we get:

sin(x)(2cos(x)1)=0\sin(x)(2\cos(x) - 1) = 0

This equation has two possible solutions: sin(x)=0\sin(x) = 0 and 2cos(x)1=02\cos(x) - 1 = 0. Solving the first equation, we get:

sin(x)=0x=0,π,2π\sin(x) = 0 \Rightarrow x = 0, \pi, 2\pi

Solving the second equation, we get:

2cos(x)1=0cos(x)=12x=π3,5π32\cos(x) - 1 = 0 \Rightarrow \cos(x) = \frac{1}{2} \Rightarrow x = \frac{\pi}{3}, \frac{5\pi}{3}

Finding the Final Solutions

Now that we have found the possible solutions for xx, we need to check if they satisfy the original equation. Plugging in the values of xx into the original equation, we get:

sin(2x)sin(x)=0\sin(2x) - \sin(x) = 0

Evaluating the expression, we get:

sin(2x)sin(x)=0sin(2π6)sin(π6)=0\sin(2x) - \sin(x) = 0 \Rightarrow \sin\left(2\cdot\frac{\pi}{6}\right) - \sin\left(\frac{\pi}{6}\right) = 0

sin(2π6)sin(π6)=sin(π3)sin(π6)=0\sin\left(2\cdot\frac{\pi}{6}\right) - \sin\left(\frac{\pi}{6}\right) = \sin\left(\frac{\pi}{3}\right) - \sin\left(\frac{\pi}{6}\right) = 0

Similarly, we can evaluate the expression for the other possible solutions:

sin(2x)sin(x)=0sin(25π6)sin(5π6)=0\sin(2x) - \sin(x) = 0 \Rightarrow \sin\left(2\cdot\frac{5\pi}{6}\right) - \sin\left(\frac{5\pi}{6}\right) = 0

sin(25π6)sin(5π6)=sin(5π3)sin(5π6)=0\sin\left(2\cdot\frac{5\pi}{6}\right) - \sin\left(\frac{5\pi}{6}\right) = \sin\left(\frac{5\pi}{3}\right) - \sin\left(\frac{5\pi}{6}\right) = 0

sin(2x)sin(x)=0sin(2π)sin(π)=0\sin(2x) - \sin(x) = 0 \Rightarrow \sin\left(2\cdot\pi\right) - \sin\left(\pi\right) = 0

sin(2π)sin(π)=sin(0)sin(π)=0\sin\left(2\cdot\pi\right) - \sin\left(\pi\right) = \sin(0) - \sin(\pi) = 0

Conclusion

In this article, we have solved the equation sin(2x)sin(x)=0\sin(2x) - \sin(x) = 0, where 0x \textless 2π0 \leq x \ \textless \ 2\pi. We have used the sum-to-product identity and the double-angle formula to rewrite the equation and solve for xx. The possible solutions for xx are {π6,5π6}\left\{\frac{\pi}{6}, \frac{5\pi}{6}\right\}.

Final Answer

The final answer is {π6,5π6}\boxed{\left\{\frac{\pi}{6}, \frac{5\pi}{6}\right\}}.

Introduction

In our previous article, we solved the equation sin(2x)sin(x)=0\sin(2x) - \sin(x) = 0, where 0x \textless 2π0 \leq x \ \textless \ 2\pi. We used the sum-to-product identity and the double-angle formula to rewrite the equation and solve for xx. In this article, we will provide a Q&A guide to help you understand the solution and apply it to other trigonometric equations.

Q: What is the sum-to-product identity?

A: The sum-to-product identity is a formula that allows us to rewrite the difference of two sine functions as a product of two functions. It is given by:

sin(a)sin(b)=2cos(a+b2)sin(ab2)\sin(a) - \sin(b) = 2\cos\left(\frac{a+b}{2}\right)\sin\left(\frac{a-b}{2}\right)

Q: How do I use the sum-to-product identity to solve trigonometric equations?

A: To use the sum-to-product identity to solve trigonometric equations, you need to identify the two sine functions in the equation and rewrite them using the sum-to-product identity. Then, you can simplify the expression and solve for the variable.

Q: What is the double-angle formula?

A: The double-angle formula is a formula that allows us to rewrite the sine of a double angle as a product of two sine functions. It is given by:

sin(2a)=2sin(a)cos(a)\sin(2a) = 2\sin(a)\cos(a)

Q: How do I use the double-angle formula to solve trigonometric equations?

A: To use the double-angle formula to solve trigonometric equations, you need to identify the double angle in the equation and rewrite it using the double-angle formula. Then, you can simplify the expression and solve for the variable.

Q: What are some common trigonometric equations that can be solved using the sum-to-product identity and the double-angle formula?

A: Some common trigonometric equations that can be solved using the sum-to-product identity and the double-angle formula include:

  • sin(a)sin(b)=0\sin(a) - \sin(b) = 0
  • cos(a)cos(b)=0\cos(a) - \cos(b) = 0
  • sin(2a)sin(a)=0\sin(2a) - \sin(a) = 0
  • cos(2a)cos(a)=0\cos(2a) - \cos(a) = 0

Q: How do I check if a solution satisfies the original equation?

A: To check if a solution satisfies the original equation, you need to plug the solution into the original equation and evaluate the expression. If the expression is equal to zero, then the solution satisfies the original equation.

Q: What are some tips for solving trigonometric equations?

A: Some tips for solving trigonometric equations include:

  • Use the sum-to-product identity and the double-angle formula to rewrite the equation.
  • Simplify the expression and solve for the variable.
  • Check if the solution satisfies the original equation.
  • Use trigonometric identities to rewrite the equation and simplify the expression.

Conclusion

In this article, we have provided a Q&A guide to help you understand the solution to the equation sin(2x)sin(x)=0\sin(2x) - \sin(x) = 0, where 0x \textless 2π0 \leq x \ \textless \ 2\pi. We have also provided some tips for solving trigonometric equations and some common trigonometric equations that can be solved using the sum-to-product identity and the double-angle formula.

Final Answer

The final answer is {π6,5π6}\boxed{\left\{\frac{\pi}{6}, \frac{5\pi}{6}\right\}}.