Answer:
x² + y² = 72
Step-by-step explanation:
The equation of a circle centred at the origin is
x² + y² = r² ( r is the radius )
The radius is the distance from the centre to a point on the circle.
Use the distance formula to calculate r
r = √ (x₂ - x₁ )² + (y₂ - y₁ )²
with (x₁, y₁ ) = (0, 0) and (x₂, y₂ ) = (6, 6)
r = [tex]\sqrt{(6-0)^2+(6-0)^2}[/tex]
= [tex]\sqrt{6^2+6^2}[/tex]
= [tex]\sqrt{36+36}[/tex]
= [tex]\sqrt{72}[/tex]
Thus
x² + y² = ([tex]\sqrt{72}[/tex] )² , that is
x² + y² = 72 ← equation of circle
