Answer:
a) -8/9
b) The series is a convergent series
c) 1/17
Step-by-step explanation:
The series a+ar+ar²+ar³⋯ =∑ar^(n−1) is called a geometric series, and r is called the common ratio.
If −1<r<1, the geometric series is convergent and its sum is expressed as ∑ar^(n−1) = a/1-r
a is the first tern of the series.
a) Rewriting the series ∑(-8)^(n−1)/9^n given in the form ∑ar^(n−1) we have;
∑(-8)^(n−1)/9^n
= ∑(-8)^(n−1)/9•(9)^n-1
= ∑1/9 • (-8/9)^(n−1)
From the series gotten, it can be seen in comparison that a = 1/9 and r = -8/9
The common ratio r = -8/9
b) Remember that for the series to be convergent, -1<r<1 i.e r must be less than 1 and since our common ratio which is -8/9 is less than 1, this implies that the series is convergent.
c) Since the sun of the series tends to infinity, we will use the formula for finding the sum to infinity of a geometric series.
S∞ = a/1-r
Given a = 1/9 and r = -8/9
S∞ = (1/9)/1-(-8/9)
S∞ = (1/9)/1+8/9
S∞ = (1/9)/17/9
S∞ = 1/9×9/17
S∞ = 1/17
The sum of the geometric series is 1/17
The answer is 2,713 in³
The volume (V) of the prop is the sum of the volume of cone (V1) and half of the volume of the sphere (V2): V = V1 + 1/2 * V2
Volume of the cone is:
V1 = π r² h / 3
According to the image,
h = 14 in
r = 9 in
and
π = 3.14
V1 = 3.14 * 9² * 14 / 3 = 1,186.92 in³
The volume of the sphere is:
V2 = π r³ * 4/3
According to the image,
r = 9 in
and
π = 3.14
V2 = 3.14 * 9³ * 4/3 = 3,052.08 in³
The volume of the prop is:
V = V1 + 1/2 * V2
V = 1,186.92 in³ + 1/2 * 3,052.08 in³
V = 1,186.92 in³ + 1,526.04 in³
V = 2,712.96 in³ ≈ 2,713 in³
Answer:
per teacher = 20 students
per tutor = 12 students
72 students = 18 tutors
Step-by-step explanation:
Divide 60 by 3 to get 20
Divide 48 by 4 to get 12
Divide 72 by 4 to get 18
To find the radius you need to decide both by two which is A- 20 and B- 5 so the difference between the two is 15
