Understanding Polar Coordinates: (3, 4π/3)
Polar coordinates offer a different way to represent points in a plane compared to the familiar Cartesian (x, y) system. Instead of using horizontal and vertical distances, polar coordinates use distance from the origin (r) and angle from the positive x-axis (θ).
Understanding (3, 4π/3)
Let's break down the polar coordinates (3, 4π/3):
- r = 3: This means the point is 3 units away from the origin.
- θ = 4π/3: This indicates an angle of 4π/3 radians measured counterclockwise from the positive x-axis. Since a full circle is 2π radians, 4π/3 represents an angle in the third quadrant, specifically 120° beyond the negative x-axis.
Converting to Cartesian Coordinates
To visualize the point and its Cartesian equivalent, we can convert the polar coordinates (3, 4π/3) to (x, y) using the following formulas:
- x = r * cos(θ)
- y = r * sin(θ)
Substituting the values:
- x = 3 * cos(4π/3) = 3 * (-1/2) = -3/2
- y = 3 * sin(4π/3) = 3 * (-√3/2) = -3√3/2
Therefore, the Cartesian coordinates of the point (3, 4π/3) are (-3/2, -3√3/2).
Visualizing the Point
Imagine a circle with radius 3 centered at the origin. Starting from the positive x-axis, rotate counterclockwise by 4π/3 radians (or 240°). The point where the radius intersects the circle represents the polar coordinates (3, 4π/3).
You can further verify that this point aligns with the Cartesian coordinates we calculated above.
Key Points
- Polar coordinates offer an alternative representation of points in a plane, especially useful when dealing with circular or radial patterns.
- The first value in polar coordinates represents distance from the origin (r), while the second value represents the angle from the positive x-axis (θ).
- Converting between polar and Cartesian coordinates allows for a better understanding of the point's location and relationships within different coordinate systems.