Math Problem Statement

Find all EXACT solutions of the equation given below in the interval [0,𝜋). 1.) sin(3x) = − sqrt(3) / 2 2.) csc(x) = 2 / sqrt(3) 3.) cos(x) = - sqrt(2) / 2

If there is more than one answer, enter them in a list separated by commas. Enter an exact expression; decimal approximations or symbolic trigonometric expressions such as arctan(5) will be marked incorrect.

x =

Solution

Let's solve each equation individually in the interval [0,π)[0, \pi).

1. sin(3x)=32\sin(3x) = -\frac{\sqrt{3}}{2}

We know that sin(θ)=32\sin(\theta) = -\frac{\sqrt{3}}{2} when: θ=4π3andθ=5π3\theta = \frac{4\pi}{3} \quad \text{and} \quad \theta = \frac{5\pi}{3} Thus: 3x=4π3and3x=5π33x = \frac{4\pi}{3} \quad \text{and} \quad 3x = \frac{5\pi}{3} Solving for xx: x=4π9andx=5π9x = \frac{4\pi}{9} \quad \text{and} \quad x = \frac{5\pi}{9} Therefore, for sin(3x)=32\sin(3x) = -\frac{\sqrt{3}}{2}: x=4π9,5π9x = \frac{4\pi}{9}, \frac{5\pi}{9}

2. csc(x)=23\csc(x) = \frac{2}{\sqrt{3}}

Since csc(x)=1sin(x)\csc(x) = \frac{1}{\sin(x)}, this equation is equivalent to: sin(x)=32\sin(x) = \frac{\sqrt{3}}{2} The solutions to sin(x)=32\sin(x) = \frac{\sqrt{3}}{2} in [0,π)[0, \pi) are: x=π3andx=2π3x = \frac{\pi}{3} \quad \text{and} \quad x = \frac{2\pi}{3} So, for csc(x)=23\csc(x) = \frac{2}{\sqrt{3}}: x=π3,2π3x = \frac{\pi}{3}, \frac{2\pi}{3}

3. cos(x)=22\cos(x) = -\frac{\sqrt{2}}{2}

We know that cos(x)=22\cos(x) = -\frac{\sqrt{2}}{2} when: x=3π4andx=5π4x = \frac{3\pi}{4} \quad \text{and} \quad x = \frac{5\pi}{4} However, since we are only interested in the interval [0,π)[0, \pi), we only take: x=3π4x = \frac{3\pi}{4} Thus, for cos(x)=22\cos(x) = -\frac{\sqrt{2}}{2}: x=3π4x = \frac{3\pi}{4}

Final Answer

Combining all solutions, we get: x=4π9,5π9,π3,2π3,3π4x = \frac{4\pi}{9}, \frac{5\pi}{9}, \frac{\pi}{3}, \frac{2\pi}{3}, \frac{3\pi}{4}

Let me know if you need further clarification on any step!


  1. What are the solutions for sin(3x)=32\sin(3x) = \frac{\sqrt{3}}{2} in [0,π)[0, \pi)?
  2. How does the range of sin(x)\sin(x) limit the solutions for csc(x)\csc(x)?
  3. What are other forms to express 32-\frac{\sqrt{3}}{2} in trigonometry?
  4. How would the solution change if we expanded the interval to [0,2π)[0, 2\pi)?
  5. Can you explain how to verify these solutions on the unit circle?

Tip: Always verify trigonometric solutions by substituting back into the original equation for accuracy!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Trigonometry
Inverse Trigonometric Functions
Solving Trigonometric Equations

Formulas

sin(θ) = -sqrt(3)/2 for θ = 4π/3 or 5π/3
csc(x) = 1/sin(x)
cos(x) = -sqrt(2)/2 for x = 3π/4 in the interval [0, π)

Theorems

Trigonometric Ratios
Unit Circle

Suitable Grade Level

Grades 10-12