Which of the following equations is of circle?
Explanation for correct option:
For option (a)
Given equation ………(1)
We have: and
Multiplying both sides of equation (1) by and we get
Multiplying both sides of equation (1) by and we get
This is an equation of a circle.
Explanation for incorrect option:
For option (b)
Given
Now
This is not an equation of a circle.
For option (c)
Given
Now
This is a linear equation.
Therefore this is not an equation of a circle.
For option (d)
Given
Now
This is not an equation of a circle.
Hence, option (a) is the correct option.