Respuesta :
The center-radius form of the circle equationis in the format (x – h)2 + (y – k)2 = r2, with the center being at the point (h, k) and the radius being "r". Therefore the radius of the circle with the given equation would be √9 or 3, first option. Hope this answers the question.
Answer: The radius of the circle is (A) 3 units.
Step-by-step explanation: The given equation of the circle is
[tex]x^2+y^2=9.~~~~~~~~~~~~~~~~~~~(i)[/tex]
We are to find the radius of the circle represented by the equation (i).
The standard form of a circle with center (g, h) and radius 'r' units is given by
[tex](x-g)^2+(y-h)^2=r^2.[/tex]
From equation (i), we have
[tex]x^2+y^2=9\\\\\Rightarrow (x-0)^2+(y-0)^2=3^2.[/tex]
This represents a circle with centre at the origin (0, 0) and radius 3 units.
Therefore, the radius of the given circle is 3 units.
Thus, (A) is the correct option.