SOLUTION: The table lists a readings for three years. ​(a) If the quadratic relationship between the carbon dioxide concentration C and the year t is expressed as Upper C equals at squar

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Question 1154243: The table lists a readings for three years.
​(a) If the quadratic relationship between the carbon dioxide concentration C and the year t is expressed as Upper C equals at squared plus bt plus c​, where t equals 0 corresponds to​ 1962, use a system of linear equations to determine the constants​ a, b, and​ c, and give the equation.
​(b) Predict the year when the amount of carbon dioxide in the atmosphere will double from its 1962 level.
Year
1962
1992
2022
CO2
318
341
371

Found 3 solutions by josgarithmetic, MathLover1, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
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expressed as Upper C equals at squared plus bt plus c​,
---------

C=at%5E2%2Bbt%2Bc


-----------
Year
1962
1992
2022
CO2
318
341
371
-----------
Year     t           CO%5B2%5D Levels
1962      0               318
1992     30               341
2022     60               371       - this has not happened yet.

Variable t was an adjustment from the given year data for easier computation for the steps and the model.

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

The table lists a readings for three years.
(a) If the quadratic relationship between the carbon dioxide concentration C and the year t+is expressed as C=at%5E2%2Bbt%2Bc, where t+equals 0 corresponds to 1962, use a system of linear equations to determine the constantsa, b, and c, and give the equation.
table:
Year|CO2level
1962|318
1992|341
2022|371


C=at%5E2%2Bbt%2Bc
since t equals 0 corresponds to 1962, and C is 318
318=a%2A0%5E2%2Bb%2A0%2Bc
highlight%28c=318%29

C=at%5E2%2Bbt%2Bc................year 1992, C=341, t=30, c=318
341=a%2A30%5E2%2Bb%2A30%2B318
900a%2B30b=341-318
900a%2B30b=23.......solve for b
b=23%2F30-900a%2F30
b=23%2F30-30a.................eq.1

C=at%5E2%2Bbt%2Bc................year 2022, C=371, t=60, c=318
371=a%2A60%5E2%2Bb%2A60%2B318
3600a%2B60b=371-318
3600a%2B60b=53
60b=53-3600a
b=+53%2F60-60a........eq.2

from eq.1 and eq.2 we have
23%2F30-30a=53%2F60-60a
30a%2B60a=53%2F60-23%2F30
90a=7%2F60
highlight%28a=7%2F5400%29

go to
b=23%2F30-30a.................eq.1, plug in+a
b=23%2F30-30%287%2F5400%29
highlight%28b=131%2F180%29
your equation is:
highlight%28C=%287%2F5400%29t%5E2%2B%28131%2F180%29t%2B318%29


(b) Predict the year when the amount of carbon dioxide in the atmosphere will double from its 1962 level.
1962 level is 318
in t+years will double which is C=2%2A318=636
636=%287%2F5400%29t%5E2%2B%28131%2F180%29t%2B318.........sole for t
%287%2F5400%29t%5E2%2B%28131%2F180%29t%2B318-636=0
%287%2F5400%29t%5E2%2B%28131%2F180%29t-319=0

using quadratic formula, we get

t+=+-1965%2F7+-+%2815+sqrt%2870753%29%29%2F7=> we need only positive root, we will disregard negative solution

t+=+%2815+sqrt%2870753%29%29%2F7+-+1965%2F7-> exact solution
t+=+288.6-> approximately

288.6 years from 1962 is: the year 2250 and the amount of carbon dioxide in the atmosphere will double from its 1962 level.




Answer by MathTherapy(10551) About Me  (Show Source):
You can put this solution on YOUR website!

The table lists a readings for three years.
​(a) If the quadratic relationship between the carbon dioxide concentration C and the year t is expressed as Upper C equals at squared plus bt plus c​, where t equals 0 corresponds to​ 1962, use a system of linear equations to determine the constants​ a, b, and​ c, and give the equation.
​(b) Predict the year when the amount of carbon dioxide in the atmosphere will double from its 1962 level.
Year
1962
1992
2022
CO2
318
341
371
The equation that person gave you is WRONG!! You need to get the correct one!! 
Anyway, when you do, the amount of time that it'll take for the carbon dioxide concentration to double from its 1962 level,
or from 318 to 636 is: