It looks like the pattern is x 10, because that's how you get from 0.02 to 0.2. So, the pattern would go 0.02, 0.2, 2, 20, 200, 2000, etc.
Answer:
f) a[n] = -(-2)^n +2^n
g) a[n] = (1/2)((-2)^-n +2^-n)
Step-by-step explanation:
Both of these problems are solved in the same way. The characteristic equation comes from ...
a[n] -k²·a[n-2] = 0
Using a[n] = r^n, we have ...
r^n -k²r^(n-2) = 0
r^(n-2)(r² -k²) = 0
r² -k² = 0
r = ±k
a[n] = p·(-k)^n +q·k^n . . . . . . for some constants p and q
We find p and q from the initial conditions.
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f) k² = 4, so k = 2.
a[0] = 0 = p + q
a[1] = 4 = -2p +2q
Dividing the second equation by 2 and adding the first, we have ...
2 = 2q
q = 1
p = -1
The solution is a[n] = -(-2)^n +2^n.
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g) k² = 1/4, so k = 1/2.
a[0] = 1 = p + q
a[1] = 0 = -p/2 +q/2
Multiplying the first equation by 1/2 and adding the second, we get ...
1/2 = q
p = 1 -q = 1/2
Using k = 2^-1, we can write the solution as follows.
The solution is a[n] = (1/2)((-2)^-n +2^-n).
20 = 40e^-0.1446t
e^-0.1446t = 0.5
t = ln 0.5 / -0.1446
t = 4.8 days
Answer:
Zara = 5
Her Dad = 30
Step-by-step explanation:
Lets say Zara's age is "z"
So, her dad's age must be 6 x z = 6z
As its given that there product is 150 so we can also write it as :
z x 6z = 150
6z to the power 2 = 150
z to the power 2 = 150 divided by 6
= 25
So, z = 5
So Zara's age is 5 so her dad's age must be 30
Answer:
D, $75.00 because 35 plus 15 plus 20 is 75.
