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3 years ago

Given f(x)=2x2+3x and g(x)=5x2−2x−6. What is (f+g)(x) ?

Mathematics

1 answer:

forsale [732]3 years ago

4 0

7x^2 + x -6

You just have to add the same terms x squared + x squared and so on

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Please solve this question. It's about inverse matrix. ASAP!!

sweet-ann [11.9K]

Answer:

Step-by-step explanation:

$A=\begin{bmatrix}2&3\\4&7\end{bmatrix}\\\\A^{-1} =\begin{bmatrix} \dfrac{7}{2} & \dfrac{-3} {2}\\-2&1 \end{bmatrix}\\\\A*A^{-1}=1\pi_2=T\\\\A^2+3T=\begin{bmatrix} 14&27\\36&61 \end{bmatrix}+\begin{bmatrix} 1&0\\0&1 \end{bmatrix}=\begin{bmatrix} 17&27\\36&64 \end{bmatrix}$

4 0

2 years ago

I dont know the x of 30-2x=22

zloy xaker [14]

Answer:

Step-by-step explanation:

30-22=2x

8=2x

8/2=x

3 0

2 years ago

Read 2 more answers

An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

Now we have everything in order to replace into formula (1):

$21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

Part b

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{350}}=7.17$

Part c

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{100}}=13.42$

Part d

As we can see when we reduce the sample size we increase the margin of error so the best option for this case is:

D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

6 0

2 years ago

A polygon has 7 sides. What is the sum of the measure of the exterior angles of the polygon?

Mariulka [41]

I think it's C, 360 degrees.

5 0

3 years ago

Read 2 more answers

Can someone help me with this problem please thank youu how do you do it ?

icang [17]

Answer:

A) x = 6 y = 6√3

Step-by-step explanation:

30-60-90 Triangle rule states that the hypothesis is 2x, the short leg is x, and the long leg is x√3. So, the short leg is 12/2 = 6, and the long leg is 6√3.

5 0

2 years ago