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2 years ago

Find the vertex of the function h(x) = x2 – 4x – 21

Mathematics

1 answer:

lakkis [162]2 years ago

7 0

Answer: (2, -25)

Step-by-step explanation:

The x coordinate of the vertex is $x=-\frac{-4}{2(1)}=2$ .

When x=2, $h(2)=2^2 - 4(2)-21=-25$ .

So, the vertex is (2, -25).

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igor_vitrenko [27]

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4 0

3 years ago

-x-1=5 can somebody answer this fo me THX :)

Nitella [24]

Answer: -6

Step-by-step explanation:

-x-1=5

-x=5+1

-x=6

divide both sides by -1

x=-6

8 0

3 years ago

Read 2 more answers

The time taken to deliver a pizza has a uniform probability distribution from 20 minutes to 60 minutes. What is the probability

Whitepunk [10]

Answer:

(1) The probability that the time to deliver a pizza is at least 32 minutes is 0.70.

(2a) The percentage of results more than 45 is 79.67%.

(2b) The percentage of results less than 85 is 91.77%.

(2c) The percentage of results are between 75 and 90 is 15.58%.

(2d) The percentage of results outside the healthy range 20 to 100 is 2.64%.

Step-by-step explanation:

(1)

Let Y = the time taken to deliver a pizza.

The random variable Y follows a Uniform distribution, U (20, 60).

The probability distribution function of a Uniform distribution is:

$f(x)=\left \{ {{\frac{1}{b-a};\ x\in [a, b] } \atop {0};\ otherwise} \right.$

Compute the probability that the time to deliver a pizza is at least 32 minutes as follows:

$P(Y\geq 32)=\int\limits^{60}_{32} {\frac{1}{b-a} } \, dx \\=\frac{1}{60-20} \int\limits^{60}_{32} {1 } \, dx\\=\frac{1}{40}\times[x]^{60}_{32}\\=\frac{1}{40}\times[60-32]\\=0.70$

Thus, the probability that the time to deliver a pizza is at least 32 minutes is 0.70.

(2)

Let X = results of a certain blood test.

It is provided that the random variable X follows a Normal distribution with parameters $\mu = 60$ and $s = 18$ .

The probabilities of a Normal distribution are computed by converting the raw scores to z-scores.

The z-scores follows a Standard normal distribution, N (0, 1).

(a)

Compute the probability that the results are more than 45 as follows:

$P(X>45)=P(\frac{X-\mu}{\sigma}> \frac{45-60}{18})=P(Z>-0.833)=P(Z$

The percentage of results more than 45 is: $0.7967\times100=79.67\%$

Thus, the percentage of results more than 45 is 79.67%.

(b)

Compute the probability that the results are less than 85 as follows:

$P(X$

The percentage of results less than 85 is: $0.9177\times100=91.77\%$

Thus, the percentage of results less than 85 is 91.77%.

(c)

Compute the probability that the results are between 75 and 90 as follows:

$P(75$

The percentage of results are between 75 and 90 is: $0.1558\times100=15.58\%$

Thus, the percentage of results are between 75 and 90 is 15.58%.

(d)

Compute the probability that the results are between 20 and 100 as follows:

$P(20$

Then the probability that the results outside the range 20 to 100 is: $1-0.9736=0.0264$ .

The percentage of results outside the range 20 to 100 is: $0.0264\times100=2.64\%$

Thus, the percentage of results outside the healthy range 20 to 100 is 2.64%.

4 0

3 years ago

the surface areas of two similar solids are 1,008cm^2 and 1,372cm^2. the volume of the larger solid is 1,801cm^3. find the volum

Anni [7]

Remember the ratios
Linear = a : b
Area = a^2 : b^2
Volume = a^3 : b^3

Hence area ratios are 1008 : 1372
Becomes linear ratios of Sqrt(1008) : sqrt(1372) :: 31.749 : 37.040
Volume ratios becomes 31.749^3 : 37.040^3 :: 32002.96 : 50817.46

Hence

32002.96 / 50817.46 = Vol (S) / 1801 cm^3
Vol(s) = 32002.96 X 1801 / 50817.46 = 1134.20cm^3 ( nearest hundredth).

8 0

3 years ago

X + 3y = 6 3x + 9y=-4 Substitution ^

kozerog [31]

Answer:

1. x + 3y = 6 answer is x = 6 − 3 y

2. 3x + 9y=-4 answer is x = − 4 3 − 3 y

but if u are talking about both of them together it has no solution

Step-by-step explanation:

4 0

3 years ago