To convert a Cartesian equation into its polar form, we need to use the relationships between polar coordinates (r, θ) and Cartesian coordinates (x, y). In polar coordinates, the following equations hold:
- x = r * cos(θ)
- y = r * sin(θ)
Given the Cartesian equation y², we’ll start off by rewriting y in terms of polar coordinates:
y = r * sin(θ)
Now, substituting this expression into the given equation, we have:
y² = (r * sin(θ))²
This results in:
y² = r² * sin²(θ)
As the original equation was simply y² (which can be treated as y² = 0), we can express this in polar coordinates accordingly:
r² * sin²(θ) = 0
This equation tells us that:
- r = 0 or sin(θ) = 0
Thus, we can derive the polar equations:
- If r = 0, we have the pole (origin) as a point.
- If sin(θ) = 0, this gives us angles where θ = nπ (n is an integer), indicating all points along the x-axis.
In conclusion, the polar representation for the curve defined purely by y² is:
r = 0 or θ = nπ
These two expressions indicate that the curve aligns with the x-axis and includes the origin as well.