How can I transform the polar equation r = 4 sin(θ) into rectangular coordinates?

To convert the polar equation r = 4 sin(θ) into rectangular coordinates, we will use the relationships between polar and rectangular coordinates:

  • x = r cos(θ)
  • y = r sin(θ)
  • r = √(x² + y²)

Starting with the polar equation:

r = 4 sin(θ)

we can express sin(θ) in terms of rectangular coordinates:

  • sin(θ) = y/r

Substituting this into the polar equation:

r = 4(y/r)

Next, we can multiply both sides by r to eliminate the fraction:

r² = 4y

Now, replace with x² + y²:

x² + y² = 4y

To rewrite this equation into a more recognizable form, we can rearrange it:

x² + y² - 4y = 0

Now, complete the square for the y terms:

  • y² – 4y can be expressed as (y – 2)² – 4.

Therefore, substituting back into the equation gives:

x² + (y - 2)² - 4 = 0

Adding 4 to both sides results in:

x² + (y - 2)² = 4

This is now the equation of a circle with a center at (0, 2) and a radius of 2.

In conclusion, the transformation of the polar equation r = 4 sin(θ) into rectangular coordinates yields the equation of a circle in the form:

x² + (y - 2)² = 4

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