Math Problem Statement

An equation is given. (Enter your answers as a comma-separated list. Let k be any integer. Round terms to three decimal places where appropriate. If there is no solution, enter NO SOLUTION.)  Find the solutions in the interval [0, 2𝜋). square root 3tan(3𝜃) + 1 = 0

Solution

To solve the equation 3tan(3θ)+1=0\sqrt{3}\tan(3\theta) + 1 = 0 in the interval [0,2π)[0, 2\pi), follow these steps:

Step 1: Isolate tan(3θ)\tan(3\theta)

3tan(3θ)+1=0\sqrt{3}\tan(3\theta) + 1 = 0 3tan(3θ)=1\sqrt{3}\tan(3\theta) = -1 tan(3θ)=13\tan(3\theta) = -\frac{1}{\sqrt{3}}

Step 2: Identify the angles where tan(x)=13\tan(x) = -\frac{1}{\sqrt{3}}

The tangent function is negative in the second and fourth quadrants. From the standard tangent values, tan(x)=13\tan(x) = -\frac{1}{\sqrt{3}} when: x=5π6andx=11π6x = \frac{5\pi}{6} \quad \text{and} \quad x = \frac{11\pi}{6}

Thus: 3θ=5π6or3θ=11π63\theta = \frac{5\pi}{6} \quad \text{or} \quad 3\theta = \frac{11\pi}{6}

Step 3: Solve for θ\theta

Divide by 3 to find θ\theta: θ=5π18andθ=11π18\theta = \frac{5\pi}{18} \quad \text{and} \quad \theta = \frac{11\pi}{18}

Step 4: General solution for tan(x)\tan(x)

The tangent function has a period of π\pi, so additional solutions for 3θ3\theta are: 3θ=5π6+nπand3θ=11π6+nπwhere nZ3\theta = \frac{5\pi}{6} + n\pi \quad \text{and} \quad 3\theta = \frac{11\pi}{6} + n\pi \quad \text{where } n \in \mathbb{Z}

Divide by 3: θ=5π18+nπ3andθ=11π18+nπ3\theta = \frac{5\pi}{18} + \frac{n\pi}{3} \quad \text{and} \quad \theta = \frac{11\pi}{18} + \frac{n\pi}{3}

Step 5: Find solutions in [0,2π)[0, 2\pi)

Generate solutions for n=0,1,2,n = 0, 1, 2, \dots until θ<2π\theta < 2\pi:

  1. For θ=5π18+nπ3\theta = \frac{5\pi}{18} + \frac{n\pi}{3}:

    • n=0:θ=5π18n = 0: \theta = \frac{5\pi}{18}
    • n=1:θ=5π18+6π18=11π18n = 1: \theta = \frac{5\pi}{18} + \frac{6\pi}{18} = \frac{11\pi}{18}
    • n=2:θ=5π18+12π18=17π18n = 2: \theta = \frac{5\pi}{18} + \frac{12\pi}{18} = \frac{17\pi}{18}
    • n=3:θ=5π18+18π18=23π18n = 3: \theta = \frac{5\pi}{18} + \frac{18\pi}{18} = \frac{23\pi}{18}
  2. For θ=11π18+nπ3\theta = \frac{11\pi}{18} + \frac{n\pi}{3}:

    • n=0:θ=11π18n = 0: \theta = \frac{11\pi}{18}
    • n=1:θ=11π18+6π18=17π18n = 1: \theta = \frac{11\pi}{18} + \frac{6\pi}{18} = \frac{17\pi}{18}
    • n=2:θ=11π18+12π18=23π18n = 2: \theta = \frac{11\pi}{18} + \frac{12\pi}{18} = \frac{23\pi}{18}
    • n=3:θ=11π18+18π18=29π18>2πn = 3: \theta = \frac{11\pi}{18} + \frac{18\pi}{18} = \frac{29\pi}{18} > 2\pi

Step 6: Final solutions

Combine the unique solutions within [0,2π)[0, 2\pi): 5π18,11π18,17π18,23π18\boxed{\frac{5\pi}{18}, \frac{11\pi}{18}, \frac{17\pi}{18}, \frac{23\pi}{18}}

Let me know if you want further clarification or have any specific questions.


Relative Questions:

  1. How do you determine the quadrant where a trigonometric function is positive or negative?
  2. Why does the tangent function have a period of π\pi?
  3. What are some common methods for solving trigonometric equations?
  4. How do you convert between radians and degrees?
  5. What other techniques can be used for equations involving square roots?

Tip: Always consider the periodicity of the trigonometric functions when solving for solutions in a specific interval.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Solving Trigonometric Equations
Periodic Functions

Formulas

tan(x) = opposite/adjacent
General solution of tangent: tan(x) = tan(y) implies x = y + nπ, n ∈ ℤ

Theorems

Tangent Function Properties
Periodic Nature of Trigonometric Functions

Suitable Grade Level

Grades 10-12