Question

HELP PLEASE!! <3
i honestly don't understand what they want me to do here

Answer 1

(a)

Explanation:

the equation of a circle centred at the origin is

x² + y² = r² ( r is the radius )

x² + y² = 20 ← is in this form , then

centre = (0, 0 ) and r =
`√(20)` =
`√(4(5))` =
`√(4)` ×
`√(5)` = 2
`√(5)`