Answer:
see explanation
Step-by-step 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 - 6)² + (y + 1)² = 40 ← is the equation of a circle in standard form
centre = (6, - 1) and r = = 2
Answer:
r=
Step-by-step explanation:
The sum to infinity of a geometric series is calculated as
S∞ = ; | r | < 1
where a₁ is the first term and r the common ratio
here a₁ = 15 and S∞ = 45 , then
45 = ( multiply both sides by (1 - r ) )
45(1 - r) = 15 ( divide both sides by 45 )
1 - r = =
( subtract 1 from both sides )
- r = - 1 = -
( multiply both sides by - 1 )
r =
