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3 years ago

Find the vertex for the equation: y=-2x^2+16x-31

Mathematics

1 answer:

Nutka1998 [239]3 years ago

7 0

Answer:

Vertex is (4,1)

Step-by-step explanation:

x=-b/2a so you need to first divide the b (second term) by the a (first term) so you should get 1 as your new a and -8 as your new b. Negative (-8) is just 8 then divide that by 2(1) which is just 2 which equals 4. That is your x. To find your y, you plug your x back into the original equation and then solve it. Hope this helps!

You might be interested in

72 = –6(y + 37)<br> plz help

AlladinOne [14]

Answer:

-49

Step-by-step explanation:

you can first divide both sides by -6

-12 = y+37

so y = -12-37 = -49

8 0

2 years ago

Does the Commutative Property of Addition apply when you add two negative integers?

MAVERICK [17]

The commutative property of addition means we can add two integers in any order. So yes, It would still apply to two negative integers (for example, -2 + -3 and -3 + -2 both equal five)

4 0

3 years ago

What is the probability that the card drawn is a diamond and a jack

SpyIntel [72]

Answer:

1/26=4/104

Step-by-step explanation:

The probability of pulling a diamond if completely shuffled properly, is a 1/4. Because there are 4 suits. This is only if, there are no jokers.

And the probability of pulling a jack, is a 4/51. Because there are 4 jacks out of the 51 cards, but you already pulled out a diamond card, so you take 1 out.

Multiply them together, and you will get 4/104 = 1/26

There is a 1/26 chance of pulling out a diamond card, then a jack.

4 0

2 years ago

Write a polynomial in factored form that has the given zeros:

wlad13 [49]

Answer:

f(x) = (x + 4)^2*(x - 5)^3

Step-by-step explanation:

For a polynomial P(x) with zeros (or roots):

x₁, x₂, ..., xₙ

And a leading coefficient (the one that multiplies the term of highest degree) A, we can write the polynomial as:

P(x) = A*(x - x₁)*(x - x₂)*...*(x - xₙ)

Now, some of these roots can be repeated.

For example if x₁ = x₂

Then we say that the root x₁ has a multiplicity of two.

And we write the polynomial as:

P(x) = A*(x - x₁)^2*(x - x₃)*....*(x - xₙ)

Now, if we have a polynomial with the roots (or zeros):

Zero at -4 with a multiplicity of 2 (we have the root x = -4 two times)

Zero at 5 with a multiplicity of 3 (we have the root x = 5 3 times)

(And a leading coefficient A = 1, I assume)

This polynomial will be written as:

f(x) = (x - (-4))*(x - (-4))*(x - 5)*(x - 5)*(x - 5)

f(x) = (x + 4)*(x + 4)*(x - 5)*(x - 5)*(x - 5)

f(x) = (x + 4)^2*(x - 5)^3

The correct option is the third one:

4 0

2 years ago

You are planning a survey of starting salaries for recent computer science majors. In a recent survey by the National Associatio

nydimaria [60]

Answer:

A sample size of 554 is needed.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.95}{2} = 0.025$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.025 = 0.975$ , so Z = 1.96.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

Standard deviation is known to be $12,000

This means that $\sigma = 12000$

What sample size do you need to have a margin of error equal to $1000, with 95% confidence?

This is n for which M = 1000. So

$M = z\frac{\sigma}{\sqrt{n}}$

$1000 = 1.96\frac{12000}{\sqrt{n}}$

$1000\sqrt{n} = 1.96*12$

Dividing both sides by 1000:

$\sqrt{n} = 1.96*12$

$(\sqrt{n})^2 = (1.96*12)^2$

$n = 553.2$

Rounding up:

A sample size of 554 is needed.

5 0

2 years ago