Convert the polar equation to a rectangular equation.

[tex]\[ r = 3 \cos \theta - \sin \theta \][/tex]

Select one:
A. None of the above
B. [tex]\( x^2 - 3x - y^2 - y = 0 \)[/tex]
C. [tex]\( x^2 - 3x + y^2 + y = 0 \)[/tex]
D. [tex]\( x^2 + 3x + y^2 + y = 0 \)[/tex]



Answer :

To convert the given polar equation [tex]\( r = 3 \cos \theta - \sin \theta \)[/tex] to a rectangular equation, follow these steps:

1. Identify the polar to rectangular transformation identities:
- [tex]\( x = r \cos \theta \)[/tex]
- [tex]\( y = r \sin \theta \)[/tex]
- [tex]\( r^2 = x^2 + y^2 \)[/tex]

2. Multiply both sides of the given polar equation by [tex]\( r \)[/tex]:
[tex]\[ r \cdot r = r \cdot (3 \cos \theta - \sin \theta) \][/tex]
Which simplifies to:
[tex]\[ r^2 = r \cdot 3 \cos \theta - r \cdot \sin \theta \][/tex]

3. Use the polar to rectangular transformation identities:
- [tex]\( r^2 = x^2 + y^2 \)[/tex]
- [tex]\( r \cos \theta = x \)[/tex]
- [tex]\( r \sin \theta = y \)[/tex]

Substitute these into the equation:
[tex]\[ x^2 + y^2 = 3x - y \][/tex]

4. Rearrange the equation to get all terms on one side:
[tex]\[ x^2 + y^2 - 3x + y = 0 \][/tex]

Therefore, the rectangular form of the given polar equation is:
[tex]\[ x^2 - 3 x + y^2 + y = 0 \][/tex]

So, the correct answer is:
c. [tex]\( x^2 - 3 x + y^2 + y = 0 \)[/tex]