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3 years ago

What is the slope of the line that passes through the points (9,4) and (9,-5)?

Mathematics

1 answer:

jeka943 years ago

6 0

Answer:

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Step-by-step explanation:

4- -5/9-9

9/0

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Distribute5x (3x + 7)

stiv31 [10]

The answer will be as shown in the pic 15x^(2) +35x

4 0

3 years ago

What is the the total cost of a book that is $45.60 with a sales tax of 7.5%

sineoko [7]

3.42 multiply 45.60 by 0.075

6 0

3 years ago

(Algebra 2) write a polynomial function of least degree with integral coefficients that has the given zeros.

saveliy_v [14]

Answer:

$x^{2} -2ix+3=0$ .

Step-by-step explanation:

Given the zeroes of the polynomial are

a=-i . and b=3i

The recquired polynomial is $(x-a)(x-b)=0$

On substituting the values of a and b we get

$(x+i)(x-3i)=0$

$x^{2} -3xi+ix-3i^{2}=0$

$x^{2} -2ix+3=0$ . (∵ $i^{2}=-1$ )

6 0

3 years ago

If S_1=1,S_2=8 and S_n=S_n-1+2S_n-2 whenever n≥2. Show that S_n=3⋅2n−1+2(−1)n for all n≥1.

Snezhnost [94]

You can try to show this by induction:

• According to the given closed form, we have $S_1=3\times2^{1-1}+2(-1)^1=3-2=1$ , which agrees with the initial value S₁ = 1.

• Assume the closed form is correct for all n up to n = k. In particular, we assume

$S_{k-1}=3\times2^{(k-1)-1}+2(-1)^{k-1}=3\times2^{k-2}+2(-1)^{k-1}$

and

$S_k=3\times2^{k-1}+2(-1)^k$

We want to then use this assumption to show the closed form is correct for n = k + 1, or

$S_{k+1}=3\times2^{(k+1)-1}+2(-1)^{k+1}=3\times2^k+2(-1)^{k+1}$

From the given recurrence, we know

$S_{k+1}=S_k+2S_{k-1}$

so that

$S_{k+1}=3\times2^{k-1}+2(-1)^k + 2\left(3\times2^{k-2}+2(-1)^{k-1}\right)$

$S_{k+1}=3\times2^{k-1}+2(-1)^k + 3\times2^{k-1}+4(-1)^{k-1}$

$S_{k+1}=2\times3\times2^{k-1}+(-1)^k\left(2+4(-1)^{-1}\right)$

$S_{k+1}=3\times2^k-2(-1)^k$

$S_{k+1}=3\times2^k+2(-1)(-1)^k$

$\boxed{S_{k+1}=3\times2^k+2(-1)^{k+1}}$

which is what we needed. QED

6 0

3 years ago

A survey of shoppers is planned to determine what percentage use credit cards. prior surveys suggest 63% of shoppers use credit

Alona [7]

We would need a sample size of 560.

We first calculate the z-score associated. with this level of confidence:
Convert 95% to a decimal: 95% = 95/100 = 0.95
Subtract from 1: 1-0.95 = 0.05
Divide by 2: 0.05/2 = 0.025
Subtract from 1: 1-0.025 = 0.975

Using a z-table (http://www.z-table.com) we see that this is associated with a z-score of 1.96.

The margin of error, ME, is given by:
$ME=z*\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}$

We want ME to be 4%; 4% = 4/100 = 0.04. Substituting this into our equation, as well as our proportion and z-score,
$0.04=1.96\sqrt{\frac{0.63(1-0.63)}{n}}
\\
\\\text{Dividing both sides by 1.96,}
\\
\\\frac{0.04}{1.96}=\sqrt{\frac{0.63(0.37)}{n}}
\\
\\\text{Squaring both sides,}
\\
\\(\frac{0.04}{1.96})^2=\frac{0.63(0.37)}{n}
\\
\\\text{Multiplying both sides by n,}
\\
\\n(\frac{0.04}{1.96})^2=0.63(0.37)
\\
\\n(\frac{0.04}{1.96})^2=0.2331
\\
\\\text{Isolating n,}
\\
\\n=\frac{0.2331}{(\frac{0.04}{1.96})^2}=559.67\approx560$

3 0

3 years ago