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3 years ago

If x = 7, find the value of a) x2 b) (x + 3)*2

Mathematics

1 answer:

Fynjy0 [20]3 years ago

3 0

Answer:

a) 49

b) 100 (I'm assuming that the 2 was supposed to be a square)

Step-by-step explanation:

Substitute the value in for x (the value being 7):

7² = 49

(7 + 3)² = (10)² = 100

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The first derivative of x^2+2y^2=16 is -x/(2y), the second is -(2y^2+x^2)/(4y^3). Find the third implicit derivative of x^2+2y^2

gtnhenbr [62]

Answer:

d³y/dx³ = (-2xy² − 3x³ − 4xy²) / (8y⁵)

Step-by-step explanation:

d²y/dx² = (-2y² − x²) / (4y³)

Take the derivative (use quotient rule and chain rule):

d³y/dx³ = [ (4y³) (-4y dy/dx − 2x) − (-2y² − x²) (12y² dy/dx) ] / (4y³)²

d³y/dx³ = [ (-16y⁴ dy/dx − 8xy³ − (-24y⁴ dy/dx − 12x²y² dy/dx) ] / (16y⁶)

d³y/dx³ = (-16y⁴ dy/dx − 8xy³ + 24y⁴ dy/dx + 12x²y² dy/dx) / (16y⁶)

d³y/dx³ = ((8y⁴ + 12x²y²) dy/dx − 8xy³) / (16y⁶)

d³y/dx³ = ((2y² + 3x²) dy/dx − 2xy) / (4y⁴)

Substitute:

d³y/dx³ = ((2y² + 3x²) (-x / (2y)) − 2xy) / (4y⁴)

d³y/dx³ = ((2y² + 3x²) (-x) − 4xy²) / (8y⁵)

d³y/dx³ = (-2xy² − 3x³ − 4xy²) / (8y⁵)

8 0

3 years ago

Read 2 more answers

A window washer earns $4 per window. Which equation represents the relationship between his total earnings and the number of win

Kaylis [27]

Let T be total of money earned and W= number of windows washed
T=4W

8 0

3 years ago

Ten years ago 53% of American families owned stocks or stock funds. Sample data collected by the Investment Company Institute in

Alborosie

Answer:

a) Null hypothesis: $p\geq 0.53$

Alternative hypothesis: $p < 0.53$

b) $z=\frac{0.46 -0.53}{\sqrt{\frac{0.53(1-0.53)}{300}}}=-2.429$

$p_v =P(Z$

c) So the p value obtained was a very low value and using the significance level given $\alpha=0.01$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 1% of significance the proportion of American families owning stocks or stock funds is significantly less than 0.53 .

Step-by-step explanation:

Data given and notation

n=300 represent the random sample taken

$\hat p=0.46$ estimated proportion of American families owning stocks or stock funds

$p_o=0.53$ is the value that we want to test

$\alpha=0.01$ represent the significance level

Confidence=99% or 0.99

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

Concepts and formulas to use

Part a

We need to conduct a hypothesis in order to test the claim that proportion is less than 0.53 or 53%.:

Null hypothesis: $p\geq 0.53$

Alternative hypothesis: $p < 0.53$

Part b

When we conduct a proportion test we need to use the z statistic, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.46 -0.53}{\sqrt{\frac{0.53(1-0.53)}{300}}}=-2.429$

Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided $\alpha=0.01$ . The next step would be calculate the p value for this test.

Since is a left tailed test the p value would be:

$p_v =P(Z$

Part c

So the p value obtained was a very low value and using the significance level given $\alpha=0.01$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 1% of significance the proportion of American families owning stocks or stock funds is significantly less than 0.53 .

7 0

2 years ago

What is an equivalent to -16m^2n-(-25m^2n)+(-7m^2n)

pantera1 [17]

Answer:

The equivalent expression is:

$-16m^2n-\left(-25m^2n\right)+\left(-7m^2n\right)=2m^2n$