(2x^4-3x^2+4x-9)÷(x+2)

A rocket is launched from a tower. The height of the rocket, y in feet, is related to the time after launch, x in seconds, by th

barxatty [35]

Step-by-step explanation:

I assume that "ground" is at 0 ft height. which is in an actual scenario not airways the case.

y = -16x² + 64x + 89

shows us that the tower is 89 ft tall (the result for x = 0, at the start).

anyway, if the original assumption is correct, then we need to solve

0 = -16x² + 64x + 89

the general solution for such a quadratic equation is

x = (-b ± sqrt(b² - 4ac))/)2a)

in our case

a = -16

b = 64

c = 89

x = (-64 ± sqrt(64² - 4×-16×89))/(2×-16) =

= (-64 ± sqrt(4096 + 5696))/-32 =

= (-64 ± sqrt(9792))/-32

x1 = (-64 + 98.95453501...)/-32 = -1.092329219... s

x2 = (-64 - 98.95453501...)/-32 = 5.092329219... s

the negative solution for time is but useful here (it would be the time calculated back to ground at the start).

so, x2 is our solution.

the rocket hits the ground after about 5.09 seconds.

5 0

2 years ago

Find 1 2/3 divided by 1 1/9. Write in simplest form.

Alex777 [14]

Answer:

you turn them into improper fractions

5/3 divided by 10/9

You never divide fractions, so you times by the reciprocal

5/3*9/10= 45/30

3/2

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

The sum of three numbers is 123. The second number is 8 more than the first. The third number is 3 times the first. What are the

Aleksandr [31]

Answer:

41 is my geuss

Step-by-step explanation:

5 0

2 years ago

Here is a simple probability model for multiple-choice tests. Suppose that each student has probability p of correctly answering

Alla [95]

Answer:

a) The probability that Jodi scores 78% or lower on a 100-question test is 4%.

b) The probability that Jodi scores 78% or lower on a 250-question test is 0.023%.

Step-by-step explanation:

a) To approximate this distribution we have to calculate the mean and the standard distribution.

The mean is the proportion p=0.85.

The standard deviation can be calculates as:

$\sigma=\sqrt{\frac{p(1-p)}{n} }= \sqrt{\frac{0.85*(1-0.85)}{100} }=0.04$

To calculate the probability that Jodi scores 78% or less on a 100-question test, we first calculate the z-value:

$z=\frac{p-p_0}{\sigma} =\frac{0.78-0.85}{0.04} =-1.75$

The probability for this value of z is

$P(x$

The probability that Jodi scores 78% or lower on a 100-question test is 4%.

b) In this case, the number of questions is 250, so the standard deviation needs to be calculated again:

$\sigma=\sqrt{\frac{p(1-p)}{n} }= \sqrt{\frac{0.85*(1-0.85)}{250} }=0.02$

To calculate the probability that Jodi scores 78% or less on a 250-question test, we first calculate the z-value:

$z=\frac{p-p_0}{\sigma} =\frac{0.78-0.85}{0.02} =-3.5$

The probability for this value of z is

$P(x$

The probability that Jodi scores 78% or lower on a 250-question test is 0.023%.

6 0

3 years ago

ONLY 1% OF PEOPLE GET THIS RIGHT AND One rabbit saw six elephants while he was going to the river. Each elephant saw two monkeys

Dvinal [7]

Answer:

31 animals

Step-by-step explanation:

1 rabbit + 6 elephants + 6*2=12monkeys + 12 parrots = 31 animals

5 0

3 years ago