Answer:
D
Step-by-step explanation:
A system of linear equations has infinite solutions when the graphs are the exact same line.
Therefore, the answer is D
9514 1404 393
Answer:
a) P(t) = 6.29e^(0.0241t)
b) P(6) ≈ 7.3 million
c) 10 years
d) 28.8 years
Step-by-step explanation:
a) You have written the equation.
P(t) = 6.29·e^(0.0241·t)
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b) 2018 is 6 years after 2012.
P(6) = 6.29·e^(0.0241·6) ≈ 7.2686 ≈ 7.3 . . . million
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c) We want t for ...
8 = 6.29·e^(0.0241t)
ln(8/6.29) = 0.0241t
t = ln(8/6.29)/0.0241 ≈ 9.978 ≈ 10.0 . . . years
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d) Along the same lines as the calculation in part (c), doubling time is ...
t = ln(2)/0.0241 ≈ 28.7613 ≈ 28.8 . . . years
The answers for the problems are: 6. -18
9. 6
12. -40
This problem deals the rate of change.
For the formula of the area of a circle, we differentiate both sides with respect to time t.
(A = πr^2) d/dt
dA/dt = 2πr (dr/dt)
Since we don't know yet the radius r, the area of a circle is given.
A = πr^2
r^2 = A/π = 4π/π
r^2 = 4
r = 2 cm
Therefore, the rate of the radius is
dA/dt = 2πr (dr/dt)
dr/dt = (dA/dt)/(2πr)
dr/dt = π/(2π*2)
dr/dt = 0.25 cm/min
Hope this helps.
