Understanding Polar Coordinates: (2, 3π/4)
Polar coordinates offer a different way to represent points in a plane compared to the familiar Cartesian coordinates (x, y). Instead of using horizontal and vertical distances, polar coordinates use distance from the origin (r) and angle from the positive x-axis (θ).
Understanding (2, 3π/4)
The point (2, 3π/4) in polar coordinates tells us the following:
- r = 2: The point is 2 units away from the origin.
- θ = 3π/4: The point is located at an angle of 3π/4 radians (or 135 degrees) counterclockwise from the positive x-axis.
Converting to Cartesian Coordinates
To convert from polar to Cartesian coordinates, use the following formulas:
- x = r cos(θ)
- y = r sin(θ)
Applying these formulas to (2, 3π/4) gives:
- x = 2 * cos(3π/4) = -√2
- y = 2 * sin(3π/4) = √2
Therefore, the Cartesian coordinates of (2, 3π/4) are (-√2, √2).
Visualizing the Point
Imagine a circle centered at the origin with radius 2. Now, starting from the positive x-axis, rotate counterclockwise by 3π/4 radians (135 degrees). The point where this rotation intersects the circle is the location of (2, 3π/4).
Key Points
- Uniqueness: While a point in Cartesian coordinates has a single representation, a point in polar coordinates has multiple representations. For example, (2, 3π/4) is equivalent to (2, -5π/4) or (2, 11π/4).
- Applications: Polar coordinates are crucial in various fields such as:
- Physics: Describing circular motion and wave phenomena.
- Engineering: Analyzing rotating systems and navigation.
- Mathematics: Graphing complex numbers and exploring curves with polar equations.
By understanding how to convert between polar and Cartesian coordinates and visualizing the representation, we can effectively work with polar coordinates and utilize their advantages in various applications.