Answer:
a) -7/9
b) 16 / (n² + 15n + 56)
c) 1
Step-by-step explanation:
When n = 1, there is only one term in the series, so a₁ = s₁.
a₁ = (1 − 8) / (1 + 8)
a₁ = -7/9
The sum of the first n terms is equal to the sum of the first n−1 terms plus the nth term.
sₙ = sₙ₋₁ + aₙ
(n − 8) / (n + 8) = (n − 1 − 8) / (n − 1 + 8) + aₙ
(n − 8) / (n + 8) = (n − 9) / (n + 7) + aₙ
aₙ = (n − 8) / (n + 8) − (n − 9) / (n + 7)
If you wish, you can simplify by finding the common denominator.
aₙ = [(n − 8) (n + 7) − (n − 9) (n + 8)] / [(n + 8) (n + 7)]
aₙ = [n² − n − 56 − (n² − n − 72)] / (n² + 15n + 56)
aₙ = 16 / (n² + 15n + 56)
The infinite sum is:
∑₁°° aₙ = lim(n→∞) sₙ
∑₁°° aₙ = lim(n→∞) (n − 8) / (n + 8)
∑₁°° aₙ = 1
Answer:
<em>L = 24,873.6 miles</em>
Step-by-step explanation:
<u>Length of the Circumference</u>
Given a circle of radius r, the length of the circumference, or line surrounding the shape is:
The Earth has a diameter of 7,917.5 miles. The radius is half the diameter:
r=7,917.5/2=3,958.75 miles
Assuming a plane flies around the equator at ground level, the distance it would travel is:
L = 24,873.6 miles
Step-by-step explanation:
I can't see picture very well but as I see first angle is
-4x+5 and second is -13x+39 ( if it isn't, correct me)
sum of this angles is 180° because they are inner angles
(-4x+5) + (-13x+39) = 180
-4x+5 -13x+39=180
-17x+44=180
-17x = 180-44
-17x= 136
x= -8
angle -4x+5 will be:
-4*-8 + 5= 32+5= 37°
840=2 times 2 times 2 times 3 times 5 times 7
The answer is definitely B
