Answer:
![\displaystyle a_{n} = (2)^{2n -1} - (3) ^{n-1 }](https://tex.z-dn.net/?f=%20%5Cdisplaystyle%20%20a_%7Bn%7D%20%20%3D%20%20%20%20%20%282%29%5E%7B2n%20-1%7D%20%20%20-%20%20%20%283%29%20%5E%7Bn-1%20%7D)
Step-by-step explanation:
we want to figure out the general term of the following recurrence relation
![\displaystyle \rm a_{n + 2} - 7a_{n + 1} + 12a_n = 0 \: \: where : \: \:a_1 = 1 \: ,a_2 = 5,](https://tex.z-dn.net/?f=%20%5Cdisplaystyle%20%5Crm%20a_%7Bn%20%2B%202%7D%20-%207a_%7Bn%20%2B%201%7D%20%2B%2012a_n%20%3D%200%20%20%5C%3A%20%20%5C%3A%20where%20%3A%20%20%5C%3A%20%20%5C%3Aa_1%20%3D%201%20%5C%3A%20%2Ca_2%20%3D%205%2C%20)
we are given a linear homogeneous recurrence relation which degree is 2. In order to find the general term ,we need to make it a characteristic equation i.e
the steps for solving a linear homogeneous recurrence relation are as follows:
- Create the characteristic equation by moving every term to the left-hand side, set equal to zero.
- Solve the polynomial by factoring or the quadratic formula.
- Determine the form for each solution: distinct roots, repeated roots, or complex roots.
- Use initial conditions to find coefficients using systems of equations or matrices.
Step-1:Create the characteristic equation
![{x}^{2} - 7x+ 12= 0](https://tex.z-dn.net/?f=%20%7Bx%7D%5E%7B2%7D%20%20-%207x%2B%2012%3D%200)
Step-2:Solve the polynomial by factoring
factor the quadratic:
![( {x}^{} - 4)(x - 3) = 0](https://tex.z-dn.net/?f=%28%20%7Bx%7D%5E%7B%7D%20%20-%204%29%28x%20-%203%29%20%3D%20%200)
solve for x:
![x = \rm 4 \:and \: 3](https://tex.z-dn.net/?f=x%20%3D%20%20%5Crm%204%20%5C%3Aand%20%5C%3A%203)
Step-3:Determine the form for each solution
since we've two distinct roots,we'd utilize the following formula:
![\displaystyle a_{n} = c_{1} {x} _{1} ^{n } + c_{2} {x} _{2} ^{n }](https://tex.z-dn.net/?f=%20%5Cdisplaystyle%20a_%7Bn%7D%20%20%3D%20c_%7B1%7D%20%20%7Bx%7D%20_%7B1%7D%20%5E%7Bn%20%7D%20%20%2B%20c_%7B2%7D%20%20%7Bx%7D%20_%7B2%7D%20%5E%7Bn%20%7D%20)
so substitute the roots we got:
![\displaystyle a_{n} = c_{1} (4)^{n } + c_{2} (3) ^{n }](https://tex.z-dn.net/?f=%20%5Cdisplaystyle%20a_%7Bn%7D%20%20%3D%20c_%7B1%7D%20%20%284%29%5E%7Bn%20%7D%20%20%2B%20c_%7B2%7D%20%20%283%29%20%5E%7Bn%20%7D%20)
Step-4:Use initial conditions to find coefficients using systems of equations
create the system of equation:
![\begin{cases}\displaystyle 4c_{1} +3 c_{2} = 1 \\ 16c_{1} + 9c_{2} = 5\end{cases}](https://tex.z-dn.net/?f=%20%20%5Cbegin%7Bcases%7D%5Cdisplaystyle%204c_%7B1%7D%20%20%20%20%2B3%20c_%7B2%7D%20%20%20%20%3D%201%20%20%5C%5C%2016c_%7B1%7D%20%20%20%20%2B%209c_%7B2%7D%20%20%20%20%20%3D%20%205%5Cend%7Bcases%7D)
solve the system of equation which yields:
![\displaystyle c_{1} = \frac{1}{2} \\ c_{2} = - \frac{1}{3}](https://tex.z-dn.net/?f=%20%5Cdisplaystyle%20c_%7B1%7D%20%20%3D%20%20%5Cfrac%7B1%7D%7B2%7D%20%20%20%20%20%5C%5C%20%20c_%7B2%7D%20%20%20%3D%20%20%20-%20%5Cfrac%7B1%7D%7B3%7D%20)
finally substitute:
![\displaystyle a_{n} = \frac{1}{2} (4)^{n } - \frac{1}{3} (3) ^{n }](https://tex.z-dn.net/?f=%20%5Cdisplaystyle%20%20a_%7Bn%7D%20%20%3D%20%20%5Cfrac%7B1%7D%7B2%7D%20%20%20%284%29%5E%7Bn%20%7D%20%20%20-%20%20%5Cfrac%7B1%7D%7B3%7D%20%20%283%29%20%5E%7Bn%20%7D)
![\displaystyle \boxed{ a_{n} = (2)^{2n-1 } - (3) ^{n -1}}](https://tex.z-dn.net/?f=%20%5Cdisplaystyle%20%5Cboxed%7B%20a_%7Bn%7D%20%20%3D%20%20%20%20%282%29%5E%7B2n-1%20%7D%20%20%20-%20%20%20%283%29%20%5E%7Bn%20-1%7D%7D)
and we're done!
Answer:
The amount that must be deposited is $ 19973.87.
Step-by-step explanation:
We have a relation between future value present value as:
F= P ![(1 +\frac{r}{n} )^{nt}](https://tex.z-dn.net/?f=%281%20%2B%5Cfrac%7Br%7D%7Bn%7D%20%20%29%5E%7Bnt%7D)
F=future value
P=present value
r=rate (as a decimal)
n=number of compounding periods per year
t=number of years
Now,
assume rate as 8%
35000= P ![(1+\frac{0.08}{12} )^{12*7}](https://tex.z-dn.net/?f=%281%2B%5Cfrac%7B0.08%7D%7B12%7D%20%29%5E%7B12%2A7%7D)
or, 35000= P × ![1.0067^{84}](https://tex.z-dn.net/?f=1.0067%5E%7B84%7D)
or, P = ![\frac{35000}{1.7522}](https://tex.z-dn.net/?f=%5Cfrac%7B35000%7D%7B1.7522%7D)
or, P = $ 19973.87
So you must deposit $ 19973.87 today.
Answer:
6
Step-by-step explanation:
Answer:
x ≈ 1.32, x ≈ - 5.32
Step-by-step explanation:
Given
x² + 4x - 7 = 0 ( add 7 to both sides )
x² + 4x = 7
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 7 + 4
(x + 2)² = 11 ( take the square root of both sides )
x + 2 = ±
( subtract 2 from both sides )
x = - 2 ± ![\sqrt{11}](https://tex.z-dn.net/?f=%5Csqrt%7B11%7D)
Thus
x = - 2 -
≈ - 5.32 ( to 2 dec. places )
x = - 2 +
≈ 1.32 ( to 2 dec. places )
Answer:
A and D
Step-by-step explanation:
Hope this helps!