Question

What is the radius of the circle whose equation is x2 + y2 = 8?

2 4 64

Answer 1

It would be

`√(8)`
Or

`2√(2)`

Answer 2

The equation of circle of radius r whose centre is the origin (0, 0) ,

It is given by:
`x^2+y^2 =r^2` ......[1]

Given the equation:
`x^2+y^2 =8`

To find the radius of the circle;

Compare the given equation with [1] we have;

`r^2 = 8`

Taking square root both sides we get;

`r = √(8) = 2√(2)` units

Therefore, the radius of the circle is,
`2√(2)` units