(1)
(a) Use the fact that [tex]\sqrt{x^2} = |x|[/tex] for all [tex]x[/tex]. Since [tex]x\to+\infty[/tex], we have [tex]x>0[/tex] and [tex]|x| = x[/tex].
[tex]\displaystyle \lim_{x\to\infty} \frac{\sqrt{9x^2 - 2}}{x + 4} = \lim_{x\to\infty} \frac{\sqrt{x^2} \sqrt{9 - \frac2{x^2}}}{x + 4} \\\\= \lim_{x\to\infty} \frac{ x \sqrt{9 - \frac2{x^2}}}{x+4} \\\\= \lim_{x\to\infty} \frac{\sqrt{9 - \frac2{x^2}}}{1 + \frac4x} \\\\= \frac{\sqrt9}1 = \boxed{3}[/tex]
(b) This time [tex]x\to-\infty[/tex], so [tex]x < 0[/tex] and [tex]|x| = -x[/tex].
[tex]\displaystyle \lim_{x\to\infty} \frac{\sqrt{9x^2 - 2}}{x + 4} = \lim_{x\to\infty} \frac{\sqrt{x^2} \sqrt{9 - \frac2{x^2}}}{x + 4} \\\\= \lim_{x\to\infty} \frac{ \boxed{-x} \sqrt{9 - \frac2{x^2}}}{x+4} \\\\= (-1) \times \lim_{x\to\infty} \frac{\sqrt{9 - \frac2{x^2}}}{1 + \frac4x} \\\\= -\frac{\sqrt9}1 = \boxed{-3}[/tex]
(c) We immediately have
[tex]\displaystyle \lim_{x\to\infty} (x - \sqrt x) = \boxed{\infty}[/tex]
since [tex]x > \sqrt x[/tex] for all [tex]x > 1[/tex].
(d) Introduce a difference of squares by factoring in the limand's conjugate. The rest mirrors what we did in (a)/(b).
[tex]\displaystyle \lim_{x\to\infty} \left(\sqrt{x^2 + 12x} - x\right) = \lim_{x\to\infty} \frac{\left(\sqrt{x^2+12x} - x\right) \left(\sqrt{x^2+12x} + x\right)}{\sqrt{x^2 + 12x} + x} \\\\ = \lim_{x\to\infty} \frac{\left(\sqrt{x^2+12x}\right)^2 - x^2}{\sqrt{x^2+12x}+x} \\\\ = \lim_{x\to\infty} \frac{12x}{\sqrt{x^2+12x}+x} \\\\ = \lim_{x\to\infty} \frac{12}{\sqrt{1 + \frac{12}x} + 1} = \frac{12}{\sqrt1 + 1} = \boxed{6}[/tex]
(e) Divide through by the highest-degree exponential term.
[tex]\displaystyle \lim_{x\to\infty} \frac{12e^{2x} - 3e^{3x}}{2e^{2x} + 4e^{3x}} = \lim_{x\to\infty} \frac{12e^{-x} - 3}{2e^{-x} + 4} = \frac{0 - 3}{0 + 4} = \boxed{-\frac34}[/tex]
(2) By definition of the derivative, we have
[tex]f'(x) = \displaystyle \lim_{h\to0} \frac{f(x+h) - f(x)}h[/tex]
For [tex]f(x) = \sqrt{x^2+1}[/tex], the limit becomes
[tex]f'(x) = \displaystyle \lim_{h\to0} \frac{\sqrt{(x+h)^2+1} - \sqrt{x^2+1}}h[/tex]
Factor in the conjugate.
[tex]f'(x) = \displaystyle \lim_{h\to0} \frac{\left(\sqrt{(x+h)^2+1} - \sqrt{x^2+1}\right) \left(\sqrt{(x+h)^2+1} + \sqrt{x^2+1}\right)}{h \left(\sqrt{(x+h)^2+1} + \sqrt{x^2+1}\right)}[/tex]
[tex]f'(x) = \displaystyle \lim_{h\to0} \frac{\left(\sqrt{(x+h)^2+1}\right)^2 - \left(\sqrt{x^2+1}\right)^2}{h \left(\sqrt{(x+h)^2+1} + \sqrt{x^2+1}\right)}[/tex]
[tex]f'(x) = \displaystyle \lim_{h\to0} \frac{\bigg((x+h)^2+1\bigg) - (x^2+1)}{h \left(\sqrt{(x+h)^2+1} + \sqrt{x^2+1}\right)}[/tex]
[tex]f'(x) = \displaystyle \lim_{h\to0} \frac{2xh + h^2}{h \left(\sqrt{(x+h)^2+1} + \sqrt{x^2+1}\right)}[/tex]
[tex]f'(x) = \displaystyle \lim_{h\to0} \frac{2x + h}{\sqrt{(x+h)^2+1} + \sqrt{x^2+1}}[/tex]
[tex]\implies \boxed{f'(x) = \displaystyle \lim_{h\to0} \frac{x}{\sqrt{x^2+1}}}[/tex]
(3) The tangent line to
[tex]y = \frac1{x^2+1}[/tex]
at the point (2, 1/5) has slope equal to the derivative [tex]\frac{dy}{dx}[/tex] when [tex]x = 2[/tex]. Compute the derivative; since [tex]y = \frac1{f(x)^2}[/tex] where [tex]f(x)[/tex] is the function from the previous problem, using the chain rule gives
[tex]y = \dfrac1{f(x)^2} \implies \dfrac{dy}{dx} = -\dfrac{2f'(x)}{f(x)^3} = -\dfrac{2 \times \frac{x}{\sqrt{x^2+1}}}{\left(\sqrt{x^2+1}\right)^3} \\\\ \implies \dfrac{dy}{dx} = -\dfrac{2x}{(x^2+1)^2}[/tex]
The tangent line at (2, 1/5) then has slope
[tex]\dfrac{dy}{dx}\bigg|_{x=2} = -\dfrac{2\times2}{(2^2+1)^2} = -\dfrac4{25}[/tex]
Using the point-slope formula, the equation of the tangent line is
[tex]y - \dfrac15 = -\dfrac4{25} (x - 2) \implies \boxed{y = -\dfrac{4x - 13}{25}}[/tex]
A group of 20 friends plays a card
game. The game can be played with
2 or more teams of equal size. Each
team must have at least 2 members.
List the possible numbers and sizes
of teams.
There can be two groups of 10 players on each team, or four groups of 5 on each team.
How many seconds did eatons baby sister sleep all together
the answer I do not know because I can not see the picture or word problem
Answer:
if said babysitter is watching my babies there better be zero seconds of sleeping so 0
What is the answer please help
help me!
Read the excerpt from A Girl Named Zippy.
Not long ago my sister Melinda shocked me by saying she had always assumed that the book on Mooreland had yet to be written because no one sane would be interested in reading it.
Why is the author shocked by what Melinda says?
A.She thought her sister believed Mooreland was exciting.
B.She had heard that her sister wanted to write a memoir.
C.She did not understand what Melinda meant by “no one sane.”
D.She did not agree with her sister that Mooreland was a boring place.
Answer:
OPTION D
Step-by-step explanation: PLS MARK BRAINLIEST :D
I dont know how to do this Please explain!!!
Using the idea that similar triangles are proportional, we can solve this problem fairly easily using a proportion. It is always best to try to draw a picture if possible, as it may increase your understanding of the problem! I have attached an image of the situation.
Proportion: The woman's distance from the laser / the woman's height = the lamp post's distance from the laser / the lamp post's height
2.1 / 1.8 = 4.5 / x
8.1 = 2.1x
x = 3.9m
Hope this helps!! :)
Please help will mark brainliest!
Answer:
chromosomes
Step-by-step explanation:
Evaluate.
(w2x−3)÷10⋅z when w=−9, x = 2.7, and z=−25
Enter your answer as a simplified mixed number in the box.
Answer:
-539.25
Step-by-step explanation:
(w^2x−3)÷10⋅z
w=−9, x = 2.7, and z=−25
((-9)^2*2.7−3)÷10⋅(-25)
Parentheses first
The exponent in the parentheses
(81*2.7−3)÷10⋅(-25)
Then multiply
(218.7−3)÷10⋅(-25)
Then subtract
(215.7)÷10⋅(-25)
Now multiply and divide from left to right
21.57*(-25)
-539.25
Answer: It's -1 2/25.
*Cho hình chóp
S ABCD .
có đáy
ABCD
là hình chữ nhật biết
AB a 2
. Tam giác
SAD
cân tại
S
và nằm trong mặt phẳng vuông góc với đáy. Biết
SC a 6
. Đặt
AD x x 0
. Giá trị của
x
theo
a
sao cho thể tích khối chóp
S ABCD .
lớn nhất là
Answer:
que
Step-by-step explanation:
no ablo ese idioma v
Graph the function (x) -7x^2
Answer:
See Picture
Step-by-step explanation:
I hope this helps!
HELPPP PLEASE!!! I’M BEING TIMED!!!!
Answer:
y= -7x -27
Step-by-step explanation:
Write the equation of the line that passes through the points (-3, -3) and (8,7).
Put your answer in fully reduced point-slope form, unless it is a vertical or horizontal
line.
Answer:
y + 3 = 10/11(x + 3)
Step-by-step explanation:
Given the points (-3, -3) and (8, 7), we can use these coordinates to solve for the slope of the line using the formula:
[tex]m = \frac{y2 - y1}{x2 - x1}[/tex]
Let (x1, y1) = (-3, -3)
(x2, y2) = (8, 7)
Substitute these values into the slope formula:
[tex]m = \frac{y2 - y1}{x2 - x1} = \frac{7 - (-3)}{8 - (-3)} = \frac{10}{11}[/tex]
Thus, slope (m) = 10/11.
Next, using the slope (m) = 10/11, and one of the given points (-3, -3), we'll substitute these values into the point-slope form:
y - y1 = m(x - x1)
Let (x1, y1) = (-3, -3)
m = 10/11
y - y1 = m(x - x1)
y - (-3) = 10/11[x - (-3)]
Simplify:
y + 3 = 10/11(x + 3) this is the point-slope form.
0.43
decimal place(s)
X 0.2
decimal place(s)
0.086
decimal place(s)
Use the cards below to create a list of steps, in order, that will solve the following equation.
3(x+6)2 = 75
Solution steps:
Add 6 to both sides
Divide both sides by 3
1
Divide both sides by
3
Subtract 6 from both sides
ay
23
Square both sides
Take the square root of both sides
If I`m going to solve "what is the percent is 29.00 out of of 122.50 what do I multiply by 100 or 122.50?
Answer:
I don't know the answer you know
PLEASE ANSWER THIS AS SOON AS POSSIBLE.
3(×+2)=3×-6 I got 0 is that right or wrong
Answer:
Step-by-step explanation:
3(x + 2) = 3x - 6
3x - 6 = 3x - 6
Subtract 6 from both sides of the equation. Then you will get 3x = 3x - 12. Now subtract 3x from both sides of the equation. Leaving you with 0 = -12. So I guess it’s correct?
please help!! will mark brainlist!
Answer:
i think its the middle one
Step-by-step explanation:
How to find the square root in long division method for 5.4289
(explanation attached)
21. You place a mat around a 25 in by 21 inch painting as shown. The mat
is twice as wide at the left and right of the painting as it is at the top an
bottom of the painting. The area of the mat is 714 square iinches (note:
the area of the border). How wide is the mat at the left and right of the
painting? At the top and bottom of the painting? (P.264 #66)
Using a quadratic equation according to the area of the rectangular mat, it is found that:
At the top and bottom of the painting, the width is 0.654 inches.At the left and right of the painting, the width is of 1.308 inches.The area of a rectangle of length l and width w is given by:
[tex]A = lw[/tex]
In this problem:
The length of the figure is of [tex]l = 25 + 4x[/tex].The width of the figure is of [tex]w = 21 + 2x[/tex].Area of 714 square inches, thus:[tex]lw = 714[/tex]
[tex](25 + 4x)(21 + 2x) = 714[/tex]
[tex]8x^2 + 134x + 525 = 714[/tex]
[tex]8x^2 + 134x - 189 = 0[/tex]
Which is a quadratic equation with [tex]a = 8, b = 134, c = -189[/tex].
The, to find the widths of the mat, we have to first find the value of x, solving the quadratic equation.
[tex]\Delta = 134^2 - 4(8)(-189) = 24004 [/tex]
[tex]x_{1} = \frac{-134 + \sqrt{24004}}{2(8)} = 0.654[/tex]
[tex]x_{2} = \frac{-134 - \sqrt{24004}}{2(8)} = -9.03[/tex]
We are interest in the positive value of x, so x = 0.654.
At the top and bottom of the painting, the width is of 0.654 inches.[tex]2(0.654) = 1.308[/tex]
At the left and right of the painting, the width is of 1.308 inches.A similar problem is given at https://brainly.com/question/14099239
Tianna works at a call center. Between 12 PM and 4 PM only 5% of her attempted calls pick up. Between 4 PM and 8PM, 15% of her attempted calls pick up. If she expects to make 80 calls between 12 PM and 4PM and 120 calls between 4 PM and 8 PM, how many total pick ups can she expect during her entire shift?
15
18
4
22
Answer:
.05(80) + .15(120)=
4 + 18 = 22
So, the total pick ups is 22.
Step-by-step explanation:
Contestants ABCDEFG and I are in a 10k race. In how many ways can C finish first and A finish second?
Answer:
I would advise you to simplify the question a little bit so that more people can understand and help you out!
Pls somone tell
Me the answer plzzzz
Answer:
POSITIVE
Step-by-step explanation:
Because the product of 2 negative numbers is a positive number
Solve the following for X:
4x + y = z
a. x = z - y - 4
b. x = z+y/4
c. x = z-y/4
d. x = z/4
Answer:
the answer is c
Step-by-step explanation:
I used brainly
Which number line graph matches the solution to -4x+2<6?
Answer:
B
Step-by-step explanation:
-4x+2<6
-4x+2 -2 < 6 -2
-4x < 4
-4x ÷ -4 < 4 ÷ -4
x < -1
If the volume of a cube is 225 cubic inches, estimate the length of each side of the cube to the nearest tenth. __in.
9514 1404 393
Answer:
6.1 in
Step-by-step explanation:
Your calculator can tell you the cube root of 225 is about 6.08220.
The side of the cube is about 6.1 inches.
_____
V = s³
∛V = s = ∛(225 in³) ≈ 6.1 in
When 8 is added to the number that is produced by doubling the number x, the result is equal to 8 times the number
that is 5 less than x. What is the value of x? Please help I will give you brainless please
answer:
x=8
Step-by-step explanation:
8+ (2x) = 8*(x-5)
8*(x-5) applies to the distributive law : a(b-c) = ab-ac
a=8 b=x c=5
8x-8*5
8x-40
then add 8+(2x) back into the equation and you have
8+(2x) = 8x-40
subtract 8
2x=8x-48
subtract 8x
-6x=-48
divide by -6
x=8
check work by plugging it in to the provided info-
8*2 = 16
16+8 = 24
8-5 = 3
3*8= 24
x=8
Convert to - 5/8 to its decimal form using long division. If your answer is a repeating decimal, make sure your decimal goes 5 place values after the decimal or the sequence of numbers that repeat if it is more that five decimal places after the decimal. *
Answer: 5/8 as a decimal is expressed as 0.625.
Hope it helps!
Brenda won 92 lollipops playing hoops at
the county fair. At school she gave four to
every student in her math class. She only
has 8 remaining. How many students are
in her class?
Answer:
21 students were given 4 lolipops
Step-by-step explanation:
Aubrey is studying for her math test. She knows she will need to round decimals to the tenths place on her test, but she forgets how to do it. Using the number 125.671 as an example, remind Aubrey the steps to rounding decimals to the nearest tenth.
Aubrey the steps to rounding decimals to the nearest tenth.
Answer:
125.7'
Step-by-step explanation:
PLEASE HELP DUE AT 12:00 PM
Answer:
A) 5; B) 32; C) 3; D) 14; E) 1/3
Step-by-step explanation:
Answer:
1. 5
2. 42
3. 3
4. 14
5. 0.3333
Step-by-step explanation:
Third Grade:
8 x 5 = 40
8 + 42 = 40
21 ÷ 7 = 3
21 - 14 = 7
---------------------------21 • x = 7
Which can be written as:
21x = 7
To solve the equation above, we need to remove the 21 on the left side to make the x alone. To do that, we divide both sides by 21.
21x/21 = 7/21
21x/21 is x and 7/21 is 0.3333 which means our equation will look like this:
x = 0.3333
Thus, the answer to "21 times what equals 7?" is 0.3333.