PLEASE HELP!! WILL GIVE BRAIN AND 5 STARS
2 answers:
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Answer:
Step-by-step explanation:
Given the series,
∑ ∞ n = 1 − 4 ( − 1 / 2 ) n − 1
I think the series is summation from n = 1 to ∞ of -4(-1/2)^(n-1)
So,
∑ − 4 ( − ½ )^(n − 1). From n = 1 to ∞
There are different types of test to show if a series converges or diverges
So, using Ratio test
Lim n → ∞ (a_n+1 / a_n)
Lim n → ∞ (-4(-1/ 2)^(n+1-1) / -4(-1/2)^(n-1))
Lim n → ∞ ((-4(-1/2)^(n) / -4(-1/2)^(n-1))
Lim n → ∞ (-1/2)ⁿ / (-1/2)^(n-1)
Lim n→ ∞ (-1/2)^(n-n+1)
Lim n→ ∞ (-1/2)^1 = -1/2
Since the limit is less than 0, then, the series converge...
Sum to infinity
Using geometric progression formula
S∞ = a / 1 - r
Where
a is first term
r is common ratio
So, first term is
a_1 = -4(-½)^1-1 = -4(-½)^0 = -4 × 1
a_1 = -4
Common ratio r = a_2 / a_1
a_2 = 4(-½)^2-1 = -4(-½)^1 = -4 × -½ = 2
a_2 = 2
Then,
r = a_2 / a_1 = 2 / -4 = -½
S∞ = -4 / 1--½
S∞ = -4 / 1 + ½
S∞ = -4 / 3/2 = -4 × 2 / 3
S∞ = -8 / 3 = -2⅔
The sum to infinity is -2.67 or -2⅔
Check attachment for better understanding
Answer:
159 m
Step-by-step explanation:
From the information given:
It was stated that if the ostrich ran towards the east direction in 7.95 s, let say the distance from the starting point is O towards the east side E, let called the distance towards the east side to be OE.
Again, the ostrich then runs in the south direction for 161 m, let the distance be OS.
Also, let the magnitude of the resultant displacement between the east direction to the south direction be ES = 226m.
We are to find, the magnitude of the ostrich's eastward component.
i.e. The distance traveled from the center to the east direction within the time frame of 7.95 s.
Using the Pythagoras rule:
ES² = OE² + OS²
226² = OE² + 161²
226² - 161² = OE²
OE² = 226² - 161²
OE² = 51076 - 25921
OE² = 51076 - 25921
OE² = 25155
OE = 158.60 m
OE ≅ 159 m
Thus, the magnitude of the ostrich's towards the eastward component. = 159 m.