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2 years ago

I'm confuse with these questions

Mathematics

1 answer:

alexdok [17]2 years ago

3 0

8 a) y=x² stretched vertically by 8

That means (0,0) stays (0,0), and (1,1) becomes (1,8) and (-1,1) becomes (-1,8)

Answer: y = 8x²

8 b) y=x² compressed vertically by 1/5

Answer: y = (1/5) x²

y = ax² + k through (-1,3) and (3,-13)

That means

3 = a (-1)² + k

-13 = a (3²) + k

Subtracting,

16 = a - 9a = -8a

a = -2

3 = -2 + k

k = 5

y = -2x² + 5

Check:

-2(-1)^2 + 5 = 3, good

-2(3)^2+5 = -18 + 5 = -13, good

Answer: a = -2, k = 5

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The sum of two numbers is 82 and their difference is 26. find each of the numbers.

Zarrin [17]

54 because if x+y=82 and x-y=26 add 26 and 82 is 108 the divide it by 2 your answer is 54

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2 years ago

Read 2 more answers

As discussed in Exercise 6.10, the General Social Survey reported a sample where about 61% of US residents thought marijuana sho

Maslowich

Answer: 2285

Step-by-step explanation:

Formula to find the sample size is given by :-

$n=p(1-p)(\dfrac{z_c}{E})^2$

, where p = prior estimate of population proportion.

E= Margin of error.

$z_c$ = z-value for confidence interval of c.

Given : Confidence interval : 95%

From the z-value table , the z-value for 95% confidence interval = $z_c=1.96$

The General Social Survey reported a sample where about 61% of US residents thought marijuana should be made legal.

i.e. the prior estimate of population proportion of US residents thought marijuana should be made legal : p=0.61

[∵ sample proportion is the best estimate for population proportion.]

Margin of error : E= 2%=0.02

Now, the required minimum sample size would be :-

$n=0.61(1-0.61)(\dfrac{1.96}{0.02})^2$

Simplify ,

$n=0.2379\times9604=2284.7916\approx2285$

Thus , we need to survey <u>2285</u> Americans .

4 0

2 years ago

What is the sum if the first 22 terms of the following series? 86 + 79 + 72 + 65 +58+...

Arturiano [62]

Seems to be an arythmetic sequence
Sn=[n(a1+an)]/2
where
Sn means sum of all terms up the nth term
n=number of terms
a1=first term
an=nth term

so from 86 to the 22th term is from a1 to a22

find teh sequence
miknus 7 each time
an=a1+d(n-1)
an=87-7(n-1)
find 22n term
a22=87-7(22-1)
a22=87-7(21)
a22=87-147
a22=-60

S22=[22(87-60)]/2
S22=[22(27)]/2
S22=594/2
S22=297

the sum is 297

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2 years ago

For the function F(x)=1/x+1, whose graph is shown below, what is the relative value of F(x) when the value of x is close to -1.

daser333 [38]

Well as x can never actually be -1 because I'm in the denominator -1 + 1 = 0 and we cannot divide by zero. But we can look at what number it approaches and i assume that is the relative value. sometimes functions will have asymptotes and others will have holes in the graph. this one would have an asymptote going down at a rapid rate. the asymptote would go on forever getting infinitely close to -1 but never touching. So I would say since the asymptote goes down forever that the graph approaches negative infinity

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2 years ago

Which statement is true?

Wittaler [7]

Answer:

The y-intercept of Function A is less than the y-intercept of Function B.

Step-by-step explanation:

Function A's y-intercept would be (0, -1) and Function B's y-intercept is (0, 4). Therefore, Function A's y-intercept is less than Function B's.

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2 years ago