Math Problem Statement

Find the terminal point P(x, y) on the unit circle determined by the given value of t. t = βˆ’ 4πœ‹ 3

Solution

To find the terminal point P(x,y)P(x, y) on the unit circle for t=βˆ’4Ο€3t = -\frac{4\pi}{3}, we follow these steps:

  1. Identify the reference angle: βˆ’4Ο€3corresponds to an angle of4Ο€3in the positive direction-\frac{4\pi}{3} \quad \text{corresponds to an angle of} \quad \frac{4\pi}{3} \quad \text{in the positive direction} since rotating by βˆ’4Ο€3-\frac{4\pi}{3} is equivalent to rotating in the opposite (clockwise) direction.

  2. Locate the terminal angle: The angle 4Ο€3\frac{4\pi}{3} in standard position is in the third quadrant because it is greater than Ο€\pi but less than 3Ο€2\frac{3\pi}{2}.

  3. Calculate coordinates on the unit circle:

    • For the unit circle, the coordinates (x,y)(x, y) for an angle of ΞΈ=4Ο€3\theta = \frac{4\pi}{3} are given by: x=cos⁑(4Ο€3)andy=sin⁑(4Ο€3)x = \cos\left(\frac{4\pi}{3}\right) \quad \text{and} \quad y = \sin\left(\frac{4\pi}{3}\right)
    • Since 4Ο€3\frac{4\pi}{3} is in the third quadrant, both cos⁑(4Ο€3)\cos\left(\frac{4\pi}{3}\right) and sin⁑(4Ο€3)\sin\left(\frac{4\pi}{3}\right) are negative.
  4. Compute the exact values: cos⁑(4Ο€3)=βˆ’12andsin⁑(4Ο€3)=βˆ’32\cos\left(\frac{4\pi}{3}\right) = -\frac{1}{2} \quad \text{and} \quad \sin\left(\frac{4\pi}{3}\right) = -\frac{\sqrt{3}}{2}

Thus, the terminal point P(x,y)P(x, y) is: P(βˆ’12,βˆ’32)P\left(-\frac{1}{2}, -\frac{\sqrt{3}}{2}\right)

Would you like further details on any part of this solution, or do you have any questions?


Here are five related questions:

  1. How would you find the terminal point for t=5Ο€3t = \frac{5\pi}{3}?
  2. What is the terminal point for t=Ο€t = \pi on the unit circle?
  3. How does one determine which quadrant a terminal point is in?
  4. What are the coordinates of the terminal point for t=βˆ’Ο€6t = -\frac{\pi}{6}?
  5. How do reference angles help in finding terminal points?

Tip: The coordinates (cos⁑(t),sin⁑(t))(\cos(t), \sin(t)) always give the terminal point on the unit circle for any angle tt.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Unit Circle
Reference Angles

Formulas

Coordinates on the unit circle for angle ΞΈ are given by (cos(ΞΈ), sin(ΞΈ))
Reference angle calculation

Theorems

Unit Circle Theorem
Reference Angle Theorem

Suitable Grade Level

Grades 9-11