Question

(x - 1)2 + (y + 3)2 = 73
What is the radius ?

Answer 1

Answer: 73 - the radius

Answer 2

radius =
`√(73)`

Explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k) are the coordinates of the centre and r is the radius

(x - 1)² + (y + 3)² = 73 ← is in standard form

with r² = 73 ( take the square root of both sides )

r =
`√(73)`