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3 years ago

Find the axis of symmetry for this parabola:

Mathematics

1 answer:

lara31 [8.8K]3 years ago

6 0

Answer:

x = - 1

Step-by-step explanation:

The equation of the axis of symmetry for a parabola in standard form

y = ax² + bx + c : a ≠ 0 is found using

x = - $\frac{b}{2a}$

y = - x² - 2x - 5 ← is in standard form

with a = - 1 and b = - 2, thus equation of axis of symmetry is

x = - $\frac{-2}{-2}$ = - 1

Equation of axis of symmetry is x = - 1

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Can some one help me please

frutty [35]

I believe The answer is B

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2 years ago

Solve for the value of n.

frosja888 [35]

Answer:

n= 27

Step-by-step explanation:

To solve first subtract the 90-degree angle:

180-90= 90

Then, convert into an equation:

3n+9= 90

Subtract 9 from both sides:

3n=81

Then divide by 3:

n= 27

Hope this helps!

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2 years ago

What is the value for y?<br> Enter your answer in the box.<br> y=

serious [3.7K]

Answer:

$y =112$

Step-by-step explanation:

Given

The attached triangle

Required

Find y

The attached triangle is isosceles; so:

$x - 5=34$

Also, we have:

$y + x - 5 + 34=180$ --- angles in a triangle

Substitute: $x - 5=34$

$y + 34 + 34=180$

Collect like terms

$y =- 34 - 34+180$

$y =112$

5 0

3 years ago

QUIZ

marta [7]

Answer:

B (5/8 - 6/8)

Step-by-step explanation:

Since we can just multiply the second fraction by two to get a similar denominator, we just need to multiply the second fraction.

5 0

3 years ago

Read 2 more answers

The prices of all college textbooks follow a bell-shaped distribution with a mean of $113 and a standard deviation of $12. Using

Soloha48 [4]

Step-by-step explanation:

In statistics, the empirical rule states that for a normally distributed random variable,

68.27% of the data lies within one standard deviation of the mean.

95.45% of the data lies within two standard deviations of the mean.

99.73% of the data lies within three standard deviations of the mean.

In mathematical notation, as shown in the figure below (for a standard normal distribution), the empirical rule is described as

$\Phi(\mu \ - \ \sigma \ \leq X \ \leq \mu \ + \ \sigma) \ = \ 0.6827 \qquad (4 \ \text{s.f.}) \\ \\ \\ \Phi(\mu \ - \ 2\sigma \ \leq X \ \leq \mu \ + \ 2\sigma) \ = \ 0.9545 \qquad (4 \ \text{s.f.}) \\ \\ \\ \Phi}(\mu \ - \ 3\sigma \ \leq X \ \leq \mu \ + \ 3\sigma) \ = \ 0.9973 \qquad (4 \ \text{s.f.})$

where the symbol $\Phi$ (the uppercase greek alphabet phi) is the cumulative density function of the normal distribution, $\mu$ is the mean and $\sigma$ is the standard deviation of the normal distribution defined as $N(\mu, \ \sigma)$ .

According to the empirical rule stated above, the interval that contains the prices of 99.7% of college textbooks for a normal distribution $N(113, \ 12)$ ,

$\Phi(113 \ - \ 3 \ \times \ 12 \ \leq \ X \ \leq \ 113 \ + \ 3 \ \times \ 12) \ = \ 0.9973 \\ \\ \\ \-\hspace{1.75cm} \Phi(113 \ - \ 36 \ \leq \ X \ \leq \ 113 \ + \ 36) \ = \ 0.9973 \\ \\ \\ \-\hspace{3.95cm} \Phi(77 \ \leq \ X \ \leq \ 149) \ = \ 0.9973$

Therefore, the price of 99.7% of college textbooks falls inclusively between $77 and $149.

5 0

2 years ago