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3 years ago

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Of 200 Boston residents surveyed, all but 18 were born in Massachusetts. What percent of the residents surveyed were not born in

Massachusetts?

1 answer:

Sonja [21]3 years ago

4 0

91 percent were not born in massachusetts

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PLEASE HELP, GOOD ANSWERS GET BRAINLIEST. +40 POINTS WRONG ANSWERS GET REPORTED

MA_775_DIABLO [31]

1. Ans:(A) 123

Given function: $f(x) = 8x^2 + 11x$
The derivative would be:
$\frac{d}{dx} f(x) = \frac{d}{dx}(8x^2 + 11x)$
=> $\frac{d}{dx} f(x) = \frac{d}{dx}(8x^2) + \frac{d}{dx}(11x)$
=> $\frac{d}{dx} f(x) = 2*8(x^{2-1}) + 11$
=> $\frac{d}{dx} f(x) = 16x + 11$

Now at x = 7:
$\frac{d}{dx} f(7) = 16(7) + 11$

=> $\frac{d}{dx} f(7) = 123$

2. Ans:(B) 3

Given function: $f(x) =3x + 8$
The derivative would be:
$\frac{d}{dx} f(x) = \frac{d}{dx}(3x + 8)$
=> $\frac{d}{dx} f(x) = \frac{d}{dx}(3x) + \frac{d}{dx}(8)$
=> $\frac{d}{dx} f(x) = 3*1 + 0$
=> $\frac{d}{dx} f(x) = 3$

Now at x = 4:
$\frac{d}{dx} f(4) = 3$ (as constant)

=>Ans: $\frac{d}{dx} f(4) =$ 3

3. Ans:(D) -5

Given function: $f(x) = \frac{5}{x}$
The derivative would be:
$\frac{d}{dx} f(x) = \frac{d}{dx}(\frac{5}{x})$
or
$\frac{d}{dx} f(x) = \frac{d}{dx}(5x^{-1})$
=> $\frac{d}{dx} f(x) = 5*(-1)*(x^{-1-1})$
=> $\frac{d}{dx} f(x) = -5x^{-2}$

Now at x = -1:
$\frac{d}{dx} f(-1) = -5(-1)^{-2}$

=> $\frac{d}{dx} f(-1) = -5 *\frac{1}{(-1)^{2}}$
=> Ans: $\frac{d}{dx} f(-1) = -5$

4. Ans:(C) 7 divided by 9

Given function: $f(x) = \frac{-7}{x}$
The derivative would be:
$\frac{d}{dx} f(x) = \frac{d}{dx}(\frac{-7}{x})$
or
$\frac{d}{dx} f(x) = \frac{d}{dx}(-7x^{-1})$
=> $\frac{d}{dx} f(x) = -7*(-1)*(x^{-1-1})$
=> $\frac{d}{dx} f(x) = 7x^{-2}$

Now at x = -3:
$\frac{d}{dx} f(-3) = 7(-3)^{-2}$

=> $\frac{d}{dx} f(-3) = 7 *\frac{1}{(-3)^{2}}$
=> Ans: $\frac{d}{dx} f(-3) = \frac{7}{9}$

5. Ans:(C) -8

Given function:
$f(x) = x^2 - 8$

Now if we apply limit:
$\lim_{x \to 0} f(x) = \lim_{x \to 0} (x^2 - 8)$

=> $\lim_{x \to 0} f(x) = (0)^2 - 8$
=> Ans: $\lim_{x \to 0} f(x) = - 8$

6. Ans:(C) 9

Given function:
$f(x) = x^2 + 3x - 1$

Now if we apply limit:
$\lim_{x \to 2} f(x) = \lim_{x \to 2} (x^2 + 3x - 1)$

=> $\lim_{x \to 2} f(x) = (2)^2 + 3(2) - 1$
=> Ans: $\lim_{x \to 2} f(x) = 4 + 6 - 1 = 9$

7. Ans:(D) doesn't exist.

Given function: $f(x) = -6 + \frac{x}{x^4}$
In this case, even if we try to simplify it algebraically, there would ALWAYS be x power something (positive) in the denominator. And when we apply the limit approaches to 0, it would always be either + infinity or -infinity. Hence, Limit doesn't exist.

Check:
$f(x) = -6 + \frac{x}{x^4} \\ f(x) = -6 + \frac{1}{x^3} \\ f(x) = \frac{-6x^3 + 1}{x^3} \\ Rationalize: \\ f(x) = \frac{-6x^3 + 1}{x^3} * \frac{x^{-3}}{x^{-3}} \\ f(x) = \frac{-6x^{3-3} + x^{-3}}{x^0} \\ f(x) = -6 + \frac{1}{x^3} \\ Same$

If you apply the limit, answer would be infinity.

8. Ans:(A) Doesn't Exist.

Given function: $f(x) = 9 + \frac{x}{x^3}$
Same as Question 7
If we try to simplify it algebraically, there would ALWAYS be x power something (positive) in the denominator. And when we apply the limit approaches to 0, it would always be either + infinity or -infinity. Hence, Limit doesn't exist.

9, 10.
Please attach the graphs. I shall amend the answer. :)

11. Ans:(A) Doesn't exist.

First We need to find out: $\lim_{x \to 9} f(x)$ where,
$f(x) = \left \{ {{x+9, ~~~~~x \textless 9} \atop {9- x,~~~~~x \geq 9}} \right.$

If both sides are equal on applying limit then limit does exist.

Let check:
If x $\textless$ 9: answer would be 9+9 = 18
If x $\geq$ 9: answer would be 9-9 = 0

Since both are not equal, as $18 \neq 0$ , hence limit doesn't exist.

12. Ans:(B) Limit doesn't exist.

Find out: $\lim_{x \to 1} f(x)$ where,

$f(x) = \left \{ {{1-x, ~~~~~x \textless 1} \atop {x+7,~~~~~x \textgreater 1} } \right. \\ and \\ f(x) = 8, ~~~~~ x=1$

If all of above three are equal upon applying limit, then limit exists.

When x < 1 -> 1-1 = 0
When x = 1 -> 8
When x > 1 -> 7 + 1 = 8

ALL of the THREE must be equal. As they are not equal. 0 $\neq$ 8; hence, limit doesn't exist.

13. Ans:(D) -∞; x = 9

f(x) = 1/(x-9).

Table:

x f(x)=1/(x-9)

----------------------------------------

8.9 -10

8.99 -100

8.999 -1000

8.9999 -10000

9.0 -∞

Below the graph is attached! As you can see in the graph that at x=9, the curve approaches but NEVER exactly touches the x=9 line. Also the curve is in downward direction when you approach from the left. Hence, -∞, x =9 (correct)

14. Ans: -6

s(t) = -2 - 6t

Inst. velocity = $\frac{ds(t)}{dt}$

Therefore,

$\frac{ds(t)}{dt} = \frac{ds(t)}{dt}(-2-6t) \\ \frac{ds(t)}{dt} = 0 - 6 = -6$

At t=2,

Inst. velocity = -6

15. Ans: +∞, x =7

f(x) = 1/(x-7)^2.

Table:

x f(x)= 1/(x-7)^2

--------------------------

6.9 +100

6.99 +10000

6.999 +1000000

6.9999 +100000000

7.0 +∞

Below the graph is attached! As you can see in the graph that at x=7, the curve approaches but NEVER exactly touches the x=7 line. The curve is in upward direction if approached from left or right. Hence, +∞, x =7 (correct)

-i

7 0

3 years ago

Read 2 more answers

What is the true solution In 20+In 5=2 In x?

S_A_V [24]

Answer:

x = 10

Step-by-step explanation:

Using the rules of logarithms

• log x + log y ⇔ log(xy)

• log $x^{n}$ ⇔ n log x

• log x = log y ⇒ x = y

Given

ln20 + ln5 = 2 lnx , then

ln(20 × 5) = ln $x^{2}$

ln 100 = ln $x^{2}$ , hence

x² = 100 ( take the square root of both sides )

x = 10

7 0

3 years ago

In the given figure, mWY = 76° and mXZ = 112. What is the difference of the measures of angle WPY and angle XPY?

skelet666 [1.2K]

Please consider the attached image for complete question.

We have been given that measure of arc WY is 76° and and measure of arc XZ is 112°. We are asked to find the difference of of the measures of angle WPY and angle XPY.

First of all we will find the measure of angle WPY using intersecting secants theorem. Intersecting secants theorem states that measure of angle formed by two intersecting secants inside a circle is half the sum of intercepting arcs.

$m\angle WPY=\frac{1}{2}(\widehat{WY}+\widehat{XZ})$

$m\angle WPY=\frac{1}{2}(76^{\circ}+112^{\circ})$

$m\angle WPY=\frac{1}{2}(188^{\circ})$

$m\angle WPY=94^{\circ}$

We can see that angle WPY and angle XPY are linear angles, so they will add up-to 180 degrees.

$m\angle WPY+m\angle XPY=180^{\circ}$

$94^{\circ}+m\angle XPY=180^{\circ}$

$94^{\circ}-94^{\circ}+m\angle XPY=180^{\circ}-94^{\circ}$

$m\angle XPY=86^{\circ}$

Now we need to find difference of both angles as:

$m\angle WPY-m\angle XPY=94^{\circ}-86^{\circ}$

$m\angle WPY-m\angle XPY=8^{\circ}$

Therefore, the difference of the measures of angle WPY and angle XPY is 8 degrees.

6 0

3 years ago

Read 2 more answers

Write four related fact. use pictures to show how the number sentences are related.

sleet_krkn [62]

Division , timetable , adding , and subtracting

8 0

3 years ago

A cone and a sphere both have a radius of 1. If you fill the cone with liquid, and pour it into the sphere, it fits exactly. Wha

PtichkaEL [24]

Answer and Step-by-step explanation:

First, solve for the volume of the sphere, then solve for the height of the cone using the volume of the sphere (which is said to be equal to the volume of the cone) and the radius given.

<u>Volume formula of Sphere</u>

V = $\frac{4}{3} \pi r^2$

<u>Substitute 1 in for r</u>

$\frac{4}{3} \pi (1)^2 = \frac{4}{3} \pi = 4.189$ = Volume

<u>Finding the Height of a Cone</u>

Volume formula for Cone: $V = \pi r^2\frac{h}{3}$

<u />

<u>Solve for </u><u><em>h</em></u>

Multiply both sides by 3, then divide by pi and r^2.

$h = \frac{3V}{\pi r^2}$

<u>Plug in the volume and the radius.</u>

$h = \frac{3(4.189)}{\pi (1)^2}$

<u>Simplify</u>

$h = \frac{12.567}{\pi }$

h ≈ 4

<u>4 is approximately the height.</u>

<u></u>

<u></u>

<u><em>#TeamTrees #PAW (Plant And Water)</em></u>

6 0

3 years ago