Math Problem Statement

Sin2x- √(3) cosx=0

Solution

To solve the equation sin(2x)3cos(x)=0\sin(2x) - \sqrt{3} \cos(x) = 0, we can use the double angle identity for sine:

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

Substituting this into the equation gives:

2sin(x)cos(x)3cos(x)=02 \sin(x) \cos(x) - \sqrt{3} \cos(x) = 0

Factoring out cos(x)\cos(x):

cos(x)(2sin(x)3)=0\cos(x) (2 \sin(x) - \sqrt{3}) = 0

This gives us two cases to consider:

  1. cos(x)=0\cos(x) = 0
  2. 2sin(x)3=02 \sin(x) - \sqrt{3} = 0

Case 1: cos(x)=0\cos(x) = 0

The solutions for cos(x)=0\cos(x) = 0 are:

x=π2+nπ,nZx = \frac{\pi}{2} + n\pi, \quad n \in \mathbb{Z}

Case 2: 2sin(x)3=02 \sin(x) - \sqrt{3} = 0

Solving for sin(x)\sin(x):

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

The solutions for this are:

x=π3+2kπandx=2π3+2kπ,kZx = \frac{\pi}{3} + 2k\pi \quad \text{and} \quad x = \frac{2\pi}{3} + 2k\pi, \quad k \in \mathbb{Z}

Final Solutions

Combining both cases, the complete solution set is:

  1. x=π2+nπx = \frac{\pi}{2} + n\pi
  2. x=π3+2kπx = \frac{\pi}{3} + 2k\pi
  3. x=2π3+2kπx = \frac{2\pi}{3} + 2k\pi

where n,kZn, k \in \mathbb{Z}.

Would you like more details on any specific part of this solution? Here are some related questions you might consider:

  1. How do you graph the function to visualize the solutions?
  2. What is the significance of the double angle identity in trigonometric equations?
  3. Can you explain the unit circle's role in finding trigonometric solutions?
  4. How can you verify these solutions using a calculator?
  5. What would the solutions look like if the equation was changed to sin(2x)+3cos(x)=0\sin(2x) + \sqrt{3} \cos(x) = 0?

Tip: Remember to check for extraneous solutions when dealing with trigonometric equations!

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Sine and Cosine Functions
Double Angle Formulas

Formulas

sin(2x) = 2sin(x)cos(x)

Theorems

Trigonometric identities

Suitable Grade Level

Grades 11-12