Find the probability for one roll of a number cube.

Two trains start from Fort Worth traveling at the same speed. The trip for Train W takes 20 hours, while the trip for Train Z ta

MrMuchimi

Answer:

The equation that best models this situation is :

b. $\frac{x}{20}=\frac{x+400}{25}$

Distance traveled by Train W = 1600 miles

Distance traveled by Train Z = 2,000 miles

Step-by-step explanation:

Given:

Time taken for Train W to complete a trip = 20 hours

Time taken for Train Z to complete a trip = 25 hours

The city Train Z is traveling to is 400 miles farther away than the city Train W is traveling to.

both trains have same speeds and start from same location.

To find the distance in total each train travels.

Solution:

<em>Let length of the trip of Train W be </em>= $x$ miles

Speed of Train W can be given as :

⇒ $\frac{Distance}{Time}$

⇒ $\frac{x}{20}\ miles/h$

<em>So, the length of the trip of Train Z will be</em> = $(x+400)$ miles

Speed of Train Z can be given as :

⇒ $\frac{Distance}{Time}$

⇒ $\frac{x+400}{25}\ miles/h$

Since the speeds are same, so the equation to find $x$ can be given as:

⇒ $\frac{x}{20}=\frac{x+400}{25}$

Solving for $x$

Multiplying both sides by 100 to remove fractions.

⇒ $100\times \frac{x}{20}=100\times \frac{x+400}{25}$

⇒ $5x=4(x+400)$

Using distribution.

⇒ $5x=4x+1600$

Subtracting both sides by $4x$

⇒ $5x-4x=4x-4x+1600$

⇒ $x=1600$

Thus, Distance traveled by Train W = 1600 miles

Distance traveled by Train Z = $1600+400$ = 2,000 miles

3 0

2 years ago

Find dy/dx implicitly and find the largest interval of the form −a < y < a or 0 < y < a such that y is a differentia

mylen [45]

Answer:

dy/dx = -1/√(1 - x²)

For 0 < y < π

Step-by-step explanation:

Given the function cos y = x

-siny dy = dx

-siny dy/dx = 1

dy/dx = -1/siny (equation 1)

But cos²y + sin²y = 1

=> sin²y = 1 - cos²y

=> siny = √(1 - cos²y) (equation 2)

Again, we know that

cosy = x

=> cos²y = x² (equation 3)

Using (equation 3) in (equation 2), we have

siny = √(1 - x²) (equation 4)

Finally, using (equation 4) in (equation 1), we have

dy/dx = -1/√(1 - x²)

The largest interval is when

√(1 - x²) = 0

=> 1 - x² = 0

=> x² = 1

=> x = ±1

So, the interval is

-1 < x < 1

arccos(1) < y < arxcos(-1)

= 0 < y < π

6 0

2 years ago

Define a function sinc(x) (pronounced "sink of x") by: text(sinc)(x)={(sin(x)/x text(if)\ x != 0, 1 text(if)\ x = 0.) (This func

gayaneshka [121]

Answer:

Step-by-step explanation:

To find the Taylor series of sinc(x) we will use the taylor series of sin(x). We have that

$\sin(x) = \sum_{n=0}^{\infty}\frac{(-1)^n x^{2n+1}}{(2n+1)!}$

which is the taylor series expansion based at 0. Then for $x\neq 0$ , by dividing both sidex by x, we have that

$\text{sinc}(x) = \frac{\sin(x)}{x}= \sum_{n=0}^{\infty}\frac{(-1)^n x^{2n}}{(2n+1)!}$

which is the taylor series expansion for the sinc function. Since the series of sine converges for every value of x. Then the taylor series of sinc converges for every value of x, but 0.

3 0

2 years ago

Two angles of a triangle measure 59° and 63°. If the longest side measures 28 centimeters, find the length of the shortest side.

Dmitrij [34]

Angles in a triangle ALWAYS equal 180 degrees, so 180-59-63= final angle (58 degrees) Then just use (Tan,Cos,Sin) with the angles to find the lengths, i can’t answer it as i don’t know what the triangle looks like

3 0

2 years ago

A doctor is measuring the average height of male students at a large college. The doctor measures the heights, in inches, of a s

denpristay [2]

Answer:

For this case the 95% confidence interval is given (63.5 , 74.4) and we want to conclude about the result. For this case we can say that the true mean of heights for male students would be between 63.5 and 74.4. And the best answer would be:

b. The doctor can be 95% confident that the mean height of male students at the college is between 63.5 inches and 74.4 inches.

Step-by-step explanation:

Notation

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

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

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

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=40-1=39$

For this case the 95% confidence interval is given (63.5 , 74.4) and we want to conclude about the result. For this case we can say that the true mean of heights for male students would be between 63.5 and 74.4. And the best answer would be:

b. The doctor can be 95% confident that the mean height of male students at the college is between 63.5 inches and 74.4 inches.

3 0

2 years ago