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3 years ago

D+fg=h (solve for the variable “g”)

Mathematics

1 answer:

Damm [24]3 years ago

5 0

Answer:

g = h/f - d/f

Step-by-step explanation:

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-4-square root of -75 / 60

Leto [7]

<span>the correct answer is -4 - 0.144337567 i</span>

3 0

3 years ago

PLEASE I NEED HELP! How do you find y?

myrzilka [38]

In this example, y is equal to 8.

In order to find this, first note that the two x value expressions create a straight line. That means when we add them together they will equal 180. this will give us a value for x.

x + 10 + 10x - 61 = 180

11x - 51 = 180

11x = 231

x = 21

Now that we have the value of x, we can do the same for the straight line created by the x + 10 angle and the 18y + 5 angle.

x + 10 + 18y + 5 = 180

(21) + 10 + 18y + 5 = 180

36 + 18y = 180

18y = 144

y = 8

4 0

3 years ago

John invests a sum of money in a

nexus9112 [7]

Answer: 0.000007638035

Step-by-step explanation:

We can use the formula for compound interest to solve this.

Now, the formula goes thus:

A = P ( 1 + r/n)^nt

Where A is the amount compounded, P is the initial amount I.e the principal, r is the rate in % , t is the time while n is the number of times the interest is compounded per time I.e how many times per year.

From the question, we get the following parameters, A = $1912.41 , P = ? , t = 15 years, r = 2.63% and n = 1 of course.

Now, we substitute these into the formula

1912.41 = P ( 1 + 2.63) ^ 15

1912.41 = P ( 3.63) ^ 15

1912.41 = P ( 250,379,850)

P = 1912.41 ÷ 250,379,850

P = 0.000007638035

Looks pretty funny an answer right?

6 0

2 years ago

The lifetime X (in hundreds of hours) of a certain type of vacuum tube has a Weibull distribution with parameters α = 2 and β =

stich3 [128]

I'm assuming $\alpha$ is the shape parameter and $\beta$ is the scale parameter. Then the PDF is

$f_X(x)=\begin{cases}\dfrac29xe^{-x^2/9}&\text{for }x\ge0\\\\0&\text{otherwise}\end{cases}$

a. The expectation is

$E[X]=\displaystyle\int_{-\infty}^\infty xf_X(x)\,\mathrm dx=\frac29\int_0^\infty x^2e^{-x^2/9}\,\mathrm dx$

To compute this integral, recall the definition of the Gamma function,

$\Gamma(x)=\displaystyle\int_0^\infty t^{x-1}e^{-t}\,\mathrm dt$

For this particular integral, first integrate by parts, taking

$u=x\implies\mathrm du=\mathrm dx$

$\mathrm dv=xe^{-x^2/9}\,\mathrm dx\implies v=-\dfrac92e^{-x^2/9}$

$E[X]=\displaystyle-xe^{-x^2/9}\bigg|_0^\infty+\int_0^\infty e^{-x^2/9}\,\mathrm x$

$E[X]=\displaystyle\int_0^\infty e^{-x^2/9}\,\mathrm dx$

Substitute $x=3y^{1/2}$ , so that $\mathrm dx=\dfrac32y^{-1/2}\,\mathrm dy$ :

$E[X]=\displaystyle\frac32\int_0^\infty y^{-1/2}e^{-y}\,\mathrm dy$

$\boxed{E[X]=\dfrac32\Gamma\left(\dfrac12\right)=\dfrac{3\sqrt\pi}2\approx2.659}$

The variance is

$\mathrm{Var}[X]=E[(X-E[X])^2]=E[X^2-2XE[X]+E[X]^2]=E[X^2]-E[X]^2$

The second moment is

$E[X^2]=\displaystyle\int_{-\infty}^\infty x^2f_X(x)\,\mathrm dx=\frac29\int_0^\infty x^3e^{-x^2/9}\,\mathrm dx$

Integrate by parts, taking

$u=x^2\implies\mathrm du=2x\,\mathrm dx$

$\mathrm dv=xe^{-x^2/9}\,\mathrm dx\implies v=-\dfrac92e^{-x^2/9}$

$E[X^2]=\displaystyle-x^2e^{-x^2/9}\bigg|_0^\infty+2\int_0^\infty xe^{-x^2/9}\,\mathrm dx$

$E[X^2]=\displaystyle2\int_0^\infty xe^{-x^2/9}\,\mathrm dx$

Substitute $x=3y^{1/2}$ again to get

$E[X^2]=\displaystyle9\int_0^\infty e^{-y}\,\mathrm dy=9$

Then the variance is

$\mathrm{Var}[X]=9-E[X]^2$

$\boxed{\mathrm{Var}[X]=9-\dfrac94\pi\approx1.931}$

b. The probability that $X\le3$ is

$P(X\le 3)=\displaystyle\int_{-\infty}^3f_X(x)\,\mathrm dx=\frac29\int_0^3xe^{-x^2/9}\,\mathrm dx$

which can be handled with the same substitution used in part (a). We get

$\boxed{P(X\le 3)=\dfrac{e-1}e\approx0.632}$

c. Same procedure as in (b). We have

$P(1\le X\le3)=P(X\le3)-P(X\le1)$

and

$P(X\le1)=\displaystyle\int_{-\infty}^1f_X(x)\,\mathrm dx=\frac29\int_0^1xe^{-x^2/9}\,\mathrm dx=\frac{e^{1/9}-1}{e^{1/9}}$

Then

$\boxed{P(1\le X\le3)=\dfrac{e^{8/9}-1}e\approx0.527}$

7 0

3 years ago

I need the answer so please help it is worth 88 points

yulyashka [42]

Answer:

Step-by-step explanation:

If she did all 3of them today then you subtract a day from each one then it would look like this

5+4+15=24

4 0

3 years ago