Math Problem Statement

Give all possible polar coordinates for the point \((-7\sqrt{3}, -7)\) given in rectangular coordinates.

Solution

To solve for all possible polar coordinates for the point (73,7)(-7\sqrt{3}, -7), let's break down the process.

  1. Convert Rectangular to Polar Coordinates: Given (x,y)=(73,7)(x, y) = (-7\sqrt{3}, -7),

    • First, find the radius rr: r=x2+y2=(73)2+(7)2=147+49=196=14r = \sqrt{x^2 + y^2} = \sqrt{(-7\sqrt{3})^2 + (-7)^2} = \sqrt{147 + 49} = \sqrt{196} = 14
  2. Find the Angle θ\theta:

    • Using tanθ=yx\tan \theta = \frac{y}{x}, tanθ=773=13=tan(π6)\tan \theta = \frac{-7}{-7\sqrt{3}} = \frac{1}{\sqrt{3}} = \tan\left(\frac{\pi}{6}\right)
    • However, since both xx and yy are negative, the point is in the third quadrant, meaning we add π\pi to the reference angle: θ=π+π6=7π6\theta = \pi + \frac{\pi}{6} = \frac{7\pi}{6}
  3. Generate Polar Coordinate Pairs:

    • The polar coordinates for this point can be written as (r,θ+2nπ)(r, \theta + 2n\pi) and (r,θ+π+2nπ)(-r, \theta + \pi + 2n\pi) for integer nn.
    • Thus, the polar coordinates are: (14,7π6+2nπ)and(14,π6+2nπ)(14, \frac{7\pi}{6} + 2n\pi) \quad \text{and} \quad (-14, \frac{\pi}{6} + 2n\pi)

Now, let's compare this with the provided answer choices. The correct answer that matches these coordinates is:

[ \boxed{\left[14, \frac{7\pi}{6} + 2n\pi\right], \left[-14, \frac{\pi}{6} + 2n\pi\right]} ]

Would you like more details on this process, or do you have further questions?

Here are some related questions you might find helpful:

  1. How are polar coordinates related to rectangular coordinates?
  2. Why is it necessary to add π\pi when finding angles in different quadrants?
  3. How do you interpret negative radius values in polar coordinates?
  4. What is the significance of adding 2nπ2n\pi in polar coordinates?
  5. How do we determine the quadrant for a point based on its coordinates?

Tip: When converting rectangular coordinates to polar, always consider the signs of xx and yy to find the correct angle quadrant.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Polar Coordinates
Rectangular Coordinates
Coordinate Conversion
Trigonometry

Formulas

r = \sqrt{x^2 + y^2}
\theta = \tan^{-1}(y / x)
(r, \theta + 2n\pi) and (-r, \theta + \pi + 2n\pi)

Theorems

Pythagorean theorem (for distance calculation)

Suitable Grade Level

Grade 11-12