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2 years ago

Given the function: f(x)=x2−x−12(x+2)(x−5)

Mathematics

1 answer:

ioda2 years ago

7 0

Answer: $x=\frac{35±\sqrt[]{6505} }{22}$

Step-by-step explanation: $x=5.25698091…,−2.07516273…$

The roots ( $zeros$ ) are the $x$ values where the graph intersects the x-axis. To find the roots ( $zeros$ ), replace $y$ with $0$ and solve for $x$ .

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What is the distance between the points (2,6) and (5,2) ?

tiny-mole [99]

Distance:

subtract (5,2)-(2,6) = (3,-4)

Compute the length (Pythagoras): sqrt( 3^2 + (-4)^2 ) = sqrt(25)=5

So, C!

7 0

3 years ago

Please help me !!!!!!!

matrenka [14]

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4 0

4 years ago

irakobra [83]

Answer:

a) P(0, 2), Q(4, 0)

b) Please find attached the plot of the points P and Q on a chart made with MS Excel

c) Please find the graph of the line that represent the function 4·x + 2·y = 8 for values of x from -2 to 3 made with the Insert Chart feature on MS Excel

Step-by-step explanation:

The given equation for the line is 4·x + 2·y = 8

a) The coordinates of P = P(0, _)

Therefore, the point 'P', which is the point where the variable y = 0, is the point the (straight line) graph intercepts the x-axis (the x-intercept)

When y = 0 from the given equation, we get;

4·x + 2·y = 8

At the point y = 0;

4·x + 2 × 0 = 8

x = 8/4 = 2

x = 2

∴ The coordinates of P = P(0, _) = P(0, 2)

Similarly, when x = 0, we get;

4·x + 2·y = 8

At the point x = 0;

4 × 0 + 2·y = 8

y = 8/2 = 4

y = 4

∴ The coordinates of Q = Q(_, 0) = Q(4, 0)

b) Rewriting the given equation in terms of 'y' gives;

y = (8 - 4·x)/2 = 4 - 2·x

y = 4 - 2·x

With the help of MS Excel, the points P and Q are plotted in the attached graph

c) The line of the graph of the function 4·x + 2·y = 8 for values of x from -2 to 3 can be added by Changing the Chart Type to 'Scatter with Smooth Lines and Markers' within MS Excel as presented in the included graph of the line.

3 0

3 years ago

Assume that foot lengths of women are normally distributed with a mean of 9.6 in and a standard deviation of 0.5 in.a. Find the

Makovka662 [10]

Answer:

a) 78.81% probability that a randomly selected woman has a foot length less than 10.0 in.

b) 78.74% probability that a randomly selected woman has a foot length between 8.0 in and 10.0 in.

c) 2.28% probability that 25 women have foot lengths with a mean greater than 9.8 in.

Step-by-step explanation:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $\frac{\sigma}{\sqrt{n}}$ .

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 9.6, \sigma = 0.5$ .

a. Find the probability that a randomly selected woman has a foot length less than 10.0 in

This probability is the pvalue of Z when $X = 10$ .

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{10 - 9.6}{0.5}$

$Z = 0.8$

$Z = 0.8$ has a pvalue of 0.7881.

So there is a 78.81% probability that a randomly selected woman has a foot length less than 10.0 in.

b. Find the probability that a randomly selected woman has a foot length between 8.0 in and 10.0 in.

This is the pvalue of Z when X = 10 subtracted by the pvalue of Z when X = 8.

When X = 10, Z has a pvalue of 0.7881.

For X = 8:

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{8 - 9.6}{0.5}$

$Z = -3.2$

$Z = -3.2$ has a pvalue of 0.0007.

So there is a 0.7881 - 0.0007 = 0.7874 = 78.74% probability that a randomly selected woman has a foot length between 8.0 in and 10.0 in.

c. Find the probability that 25 women have foot lengths with a mean greater than 9.8 in.

Now we have $n = 25, s = \frac{0.5}{\sqrt{25}} = 0.1$ .

This probability is 1 subtracted by the pvalue of Z when $X = 9.8$ . So:

$Z = \frac{X - \mu}{s}$

$Z = \frac{9.8 - 9.6}{0.1}$

$Z = 2$

$Z = 2$ has a pvalue of 0.9772.

There is a 1-0.9772 = 0.0228 = 2.28% probability that 25 women have foot lengths with a mean greater than 9.8 in.

5 0

4 years ago

A mathematics instructor wants to see if a computer homework system improves the scores of the students in the class. The instru

Vilka [71]

Answer:

Step-by-step explanation:

Two samples are matched pairs if the samples are dependent sample. All the attributes or characteristics of these samples are the same except the one thing which we need to study or experiment.

The given samples are independent samples. So, these these two sample are not matched pair samples. Such samples cannot be used to perform the paired sample t test. For this test the samples must always be dependent.

Example of dependent or matched pairs samples under given scenario would be like:

The instructor teaches a section in one semester using the computer homework system and in the next semester he teaches the same section using the paper and pencil homework system.

Usually the pairs in matched pairs are the same people just at different time, as stated in the previous example.

4 0

4 years ago