Encuentre la suma: 564 + 3,598 =? 3,034 4,052 4,162 9,238

Determine whether the given signal is a solution to the difference equation. Then find the general solution to the difference eq

Ulleksa [173]

Answer:

The answer to this question can be defined as follows:

Step-by-step explanation:

The given equation is:

$y_{k + 2} + 8y_{k +1} - 9y_{k} = 20k + 12..(1)$

put,

$y_k = k^2\\\\y_{k+2}=(k+2)^2\\\\y_{k+1}=(k+1)^2\\\\$

$(k+2)^2+8(K+1)^2-9k^2 = 20k+12\\\\=20k+12= 20K+12\\\\$

hence y_k=k^2 is its solution.

Now,

$\to y_{k+2}+ 8y_k + 1 - 9y_k = 20k + 12$

the symbol form is:

$(E^2+8E-9)_{yk}=20k+12$

$\to m^2+8m-9=0\\\\\to m^2+(9-1)m-9=0\\\\\to m^2+9m-m-9=0\\\\\to m(m+9)-(m+9)=0\\\\\to (m+9)(m-1)=0\\\\\to m=-9 \ \ \ \ \ \ \ m=1\\$

The general solution is:

$y_k = c_1(-9)^k + c_2(`1)^k\\\\y_k =c_1(-9)^k+c_2$

The complete solution is:

$y_k=(y_k)_c+(y_k)_y\\\\y_k= c_1(-9)^k+c_2+k^2$

The answer is option b: $y_k = k^2 + c_1(-9)^k + c_2$

After solve the complete solution is:

$\bold{y_1=c_1(-9)^k+c_2+k^2.....}$

5 0

2 years ago

Please help with these Math question's ASP.

vodomira [7]

Answer:

See below in bold.

Step-by-step explanation:

1. x/8 = 15/24

Cross multiplying:

24x = 8*15

x = (8*15)/24

x = 5.

2. 5/6 = 35/x

5x = 6*35

5x = 210

x = 210/5

x = 42.

3. 18/42

Divide top and bottom by 6:

18 / 6 / 42/6

= 3/7.

4. 15/75

Divide top and bottom by 15:

= 1/5.

5 0

3 years ago

.5n-9=4n+5 pls i need help

Oksana_A [137]

Hi there,

5n - 9 + 4n + 5
5n - 4n = 5 + 9

Hence, N = 14

Hope this helps :)

3 0

2 years ago

PTC is a substance that has a strong bitter taste for some people and is tasteless for others. The ability to taste PTC is inher

lana66690 [7]

Answer:

a) $n=\frac{0.76(1-0.76)}{(\frac{0.01}{1.64})^2}=4905.83$

And rounded up we have that n=4906

b) For this case since we don't have prior info we need to use as estimatro for the proportion $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{1.64})^2}=6724$

And rounded up we have that n=6724

Step-by-step explanation:

We need to remember that the confidence interval for the true proportion is given by :

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

Part a

The estimated proportion for this case is $\hat p =0.76$

Our interval is at 90% of confidence, and the significance level is given by $\alpha=1-0.90=0.1$ and $\alpha/2 =0.05$ . The critical values for this case are:

$z_{\alpha/2}=-1.64, t_{1-\alpha/2}=1.64$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

The margin of error desired is given $ME =\pm 0.01$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Replacing we got:

$n=\frac{0.76(1-0.76)}{(\frac{0.01}{1.64})^2}=4905.83$

And rounded up we have that n=4906

Part b

For this case since we don't have prior info we need to use as estimatro for the proportion $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.01}{1.64})^2}=6724$

And rounded up we have that n=6724

3 0

3 years ago

If x-1/x=5 find x^3+1/x^3=?

ipn [44]

$\dfrac{x-1}{x}=5\ \ \ \ /x\neq0\\\\\dfrac{x-1}{x}=\dfrac{5}{1}\ \ \ \ |\text{cross multiply}\\\\5x=x-1\ \ \ \ |-x\\\\5x=1\ \ \ \ |:5\\\\x=0.2\\\\\dfrac{x^3+1}{x^3}=\dfrac{x^3}{x^3}+\dfrac{1}{x^3}=1+\dfrac{1}{x^3}\to1+\dfrac{1}{0.2^3}=1+\dfrac{1}{0.008}\\\\=1+\dfrac{1}{\frac{8}{1,000}}=1+\dfrac{1,000}{8}=1+125=126\\\\\text{Answer:}\ \dfrac{x^3+1}{x^3}=126$

5 0

3 years ago

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