Answer:
- P(t) = 100·2.3^t
- 529 after 2 hours
- 441 per hour, rate of growth at 2 hours
- 5.5 hours to reach 10,000
Step-by-step explanation:
It often works well to write an exponential expression as ...
value = (initial value)×(growth factor)^(t/(growth period))
(a) Here, the growth factor for the bacteria is given as 230/100 = 2.3 in a period of 1 hour. The initial number is 100, so we can write the pupulation function as ...
P(t) = 100·2.3^t
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(b) P(2) = 100·2.3^2 = 529 . . . number after 2 hours
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(c) P'(t) = ln(2.3)P(t) ≈ 83.2909·2.3^t
P'(2) = 83.2909·2.3^2 ≈ 441 . . . bacteria per hour
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(d) We want to find t such that ...
P(t) = 10000
100·2.3^t = 10000 . . . substitute for P(t)
2.3^t = 100 . . . . . . . . divide by 100
t·log(2.3) = log(100)
t = 2/log(2.3) ≈ 5.5 . . . hours until the population reaches 10,000
Answer:
36
Step-by-step explanation:
5 x 4 = 20
20 x 2 = 40
40 x 2 = 80
80 ÷ 2 = 40
40 - 4 = 36
6x^3 a negative times a negative cancels out making it positive
Answer:
A.128
Step-by-step explanation:
First you break the prism apart so that you have one 7x4x2 rectangular prism and one 12x3x2 prism. Find the volume of both, then add them together.
Volume of 12x3x2:
12 x 3 = 36. 36 x 2 = 72.
Volume of 7x4x2:
7 x 4 = 28. 28 x 2=56.
Then add both volumes: 72 + 56 = 128.