Step-by-step explanation:
Content
Functions and their inverses
We begin with a simple example.
Example
Let f(x)=2x and g(x)=x2.
Apply the function g to the number 3, and then apply f to the result:
g(3)=32andf(32)=3.
A similar thing happens if we first apply f and then apply g:
f(3)=6andg(6)=3.
It is clear that this will happen with any starting number. This is expressed as
f(g(x))g(f(x))=x,for all x=x,for all x.
The function f reverses the effect of g, and the function g reverses the effect of f. We say that f and g are inverses of each other.
As another example, we have
(x−−√3)3=xandx3−−√3=x,
for all real x. So the functions f(x)=x3 and g(x)=x−−√3 are inverses of each other.
If x≥0, then (x−−√)2=x and x2−−√=x. If x<0, then x−−√ is not defined. So the functions f(x)=x2 and g(x)=x−−√ are inverses of each other, but we need to be careful about domains. We will look at this more carefully later in this section.
Basics
In an earlier section of this module, we defined the composite of two functions h and g by (g∘h)(x)=g(h(x)).
Definitions
The zero function 0–:R→R is defined by 0–(x)=0, for all x.
The identity function id:R→R is defined by id(x)=x, for all x.
Example
Consider a function f:R→R.
Prove that
0–∘f=0–
f∘id=f
id∘f=f.
Show that f∘0– does not necessarily equal 0–.
Solution
We have (0–∘f)(x)=0–(f(x))=0, for all x, and so 0–∘f=0–.
We have (f∘id)(x)=f(id(x))=f(x), for all x, and so f∘id=f.
We have (id∘f)(x)=id(f(x))=f(x), for all x, and so id∘f=f.
Consider the function given by f(x)=2, for all x. Then f∘0–(x)=f(0–(x))=f(0)=2, and so f∘0–≠0–.
Definition
Let f be a function with both domain and range all real numbers. Then the function g is the inverse of f if
f(g(x))g(f(x))=x,for all x,and=x,for all x.
That is, f∘g=id and g∘f=id.
Notes.
Clearly, if g is the inverse of f, then f is the inverse of g.
We denote the inverse of f by f−1. We read f−1 as 'f inverse'. Note that f inverse has nothing to do with the function 1f.
Example
Let f(x)=x+2 and let g(x)=x−2. Show that f and g are inverses of each other.
Solution
We have
f(g(x))=f(x−2)=x−2+2=x,for all x(f∘g=id)
and
g(f(x))=g(x+2)=x+2−2=x,for all x(g∘f=id).
Hence, the functions f and g are inverses of each other.
Exercise 5
Find the inverse of
f(x)=x+7
f(x)=4x+5.
Example
Let f(x)=ax+b with a≠0. Find the inverse of f.
Solution
We have x=f(x)−ba, for all x. So let g(x)=x−ba. Then
f(g(x))g(f(x))=f(x−ba)=a(x−ba)+b=x=g(ax+b)=(ax+b)−ba=x,
for all x. Hence, g is the inverse of f.
Exercise 6
Show that f(x)=x5 and g(x)=x15 are inverses of each other.
Find the inverse of f(x)=x3+2.
We do not yet have a general enough concept of inverses, since x2 and x−−√ do not fit into this framework, nor do ex and logex. We will give a definition that covers these functions later in this section.
The horizontal-line test
Consider the function f(x)=x2, which has domain the reals and range A={x:x≥0}. Does f have an inverse?
The following graph shows that it does not. We have f(−2)=f(2)=4, and so f−1(4) would have to take two values, −2 and 2! Hence, f does not have an inverse.
Graph of y = x squared and the line y = 4 on the one set of axes.
This idea can be formulated as a test.
Horizontal-line test
Let f be a function. If there is a horizontal line y=c that meets the graph y=f(x) at more than one point, then f does not have an inverse.
Notes. Remember that the vertical-line test determines whether a relation is a function.
Example
Consider the function
f(x)=x3−x=(x+1)x(x−1).
Its graph is shown in the following diagram.
Graph of y = x cubed minus x.
Does f have an inverse?
Solution
The line y=0 meets the graph at three points. By the horizontal-line test, the function f does not have an inverse.
The function whose inverse does not exist is f(x) = x(x - 1)
The correct option is (D) f(x) = x(x - 1)
What is inverse of a function?An inverse is a function that serves to “undo” another function. That is, if f(x) produces y, then putting y into the inverse of f produces the output x.
First, f(x)= [tex]\frac{1}{2} x -\frac{1}{2}[/tex]
let y= [tex]\frac{1}{2} x -\frac{1}{2}[/tex]
On solving for x we get a unique value
Then replace x and y.
It shows that the function have a unique value, which satisfies the condition of inverse.
Now, f(x) =[tex](x - 1)^3 + 2[/tex]
Again, solving for y we can get a cube root function which is a inverse of cube.
Hence, the inverse of [tex](x - 1)^3 + 2[/tex] exists.
Next, f(x) =[tex]2^x[/tex]
Solving for above we get logarithmic value. Log function are inverse of exponential function.
Hence, the inverse of [tex]2^x[/tex] exists.
Last, f(x)= x(x-1)
Solving for above create a square value.
The inverse of square never exist because having square root gives two value one is positive and other is negative.
Hence, the inverse of x(x-1) not exists.
Hence the function whose inverse does not exist is x(x-1).
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50×54+35-44
Simplification
no spam
steps must
Answer:
=2691
Step-by-step explanation:
=2700+35−44
=2735−44
=2691
Noah bought 15 baseball cards for $9.00 assuming each baseball card cost the same amount answer the following questions
Answer:
Well, each baseball card $1.60.
Step-by-step explanation:
Since, you may just divide the amount of cards to the amount of money required.
A salesperson earns an income of $600 per week aus an dditional 5% commission on her total sales for that weck a. Write an equation that models the Salespersons total weekly income. b. What would be the salespersons income if her total sales were $10.000 that week? c. How much would a salesperson have to sell to have a $2000 weekly
Trong 300 người bệnh chỉ dùng thuốc A có 55% người khỏi; trong 240 người bệnh chỉ dùng thuốc B có 50% người khỏi. Với mức ý nghĩa 5% có thể nói thuốc A hiệu quả hơn thuốc B không?
vâng vì phụ nữ là những người tán gẫu
b. What is the number that is halfway between the two values?
7 and 11
Submit
Answer:
9
Step-by-step explanation:
It would be 9 because 7 +2 is 9 and 11 - 2 is 9.
Isn't way to hard.
Good luck on whatever you are doing.
9514 1404 393
Answer:
9
Step-by-step explanation:
The midpoint between two values is their average. The average is half their sum.
(7 +11)/2 = 18/2 = 9
The number 9 is halfway between 7 and 11.
_____
Check
The distance from 7 to 9 is 9-7 = 2. The distance from 9 to 11 is 11-9 = 2. The distances are the same, so 9 is halfway between 7 and 11.
Dell Computers receives large shipments of microprocessors (chips) from Intel Corp. It must try to ensure that the proportion of defective chips is small and has contracted to keep the proportion of defective chips at 5% or less. Suppose that Dell tests 25 chips (with replacement) out of a shipment of thousands.
a) What is the probability of obtaining at least three defects in the sample, if the entire shipment has 5% defectives? If a sample results in at least three defects, does it appear that Intel has provided a shipment which is consistent with the contract? Briefly explain, using the calculated probability.
b) For the shipment described in part a, find the expected number of sampled chips that are defective and the standard deviation of the number of sampled chips that are defective.
c) Suppose that 20% of the entire shipment is defective. What is the probability that more than 17 chips in the sample are good (not defective)?
Using the binomial distribution, it is found that:
a) 0.1271 = 12.71% probability of obtaining at least three defects in the sample, if the entire shipment has 5% defectives. 5% defective is between 1 and 2 defects, but since this probability is more than the unlikely threshold 5%, more than 2 defects could still mean that Intel has provided a shipment which is consistent with the contract.
b) The mean is of 1.25 defective chips and the standard deviation is of 1.09 defective chips.
c) 0.8908 = 89.08% probability that more than 17 chips in the sample are good.
For each chip, there are only two possible outcomes, either it is defective, or it is not. The probability of a chip being defective is independent of any other chip, which means that the binomial distribution is used to solve this question.
Binomial probability distribution
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
x is the number of successes. n is the number of trials. p is the probability of a success on a single trial.In this problem:
25 chips are tested, thus, [tex]n = 25[/tex].Item a:
Supposing 5% defective, we have that [tex]p = 0.05[/tex].
The probability is:
[tex]P(X \geq 3) = 1 - P(X < 3)[/tex]
In which
[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)[/tex]
Then
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{25,0}.(0.05)^{0}.(0.95)^{25} = 0.2774[/tex]
[tex]P(X = 1) = C_{25,1}.(0.05)^{1}.(0.95)^{24} = 0.3650[/tex]
[tex]P(X = 2) = C_{25,2}.(0.05)^{2}.(0.95)^{23} = 0.2305[/tex]
[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2) = 0.2774 + 0.3650 + 0.2305 = 0.8729[/tex]
[tex]P(X \geq 3) = 1 - P(X < 3) = 1 - 0.8729 = 0.1271[/tex]
0.1271 = 12.71% probability of obtaining at least three defects in the sample, if the entire shipment has 5% defectives. 5% defective is between 1 and 2 defects, but since this probability is more than the unlikely threshold 5%, more than 2 defects could still mean that Intel has provided a shipment which is consistent with the contract.
Item b:
The mean is:
[tex]E(X) = np = 25(0.05) = 1.25[/tex]
The standard deviation is:
[tex]\sqrt{V(X)} = \sqrt{np(1 - p)} = \sqrt{25(0.05)(0.95)} = 1.09[/tex]
The mean is of 1.25 defective chips and the standard deviation is of 1.09 defective chips.
Item c:
20% are defective, so 80% are good, which means that [tex]p = 0.8[/tex]
The probability is:
[tex]P(X > 17) = P(X = 18) + P(X = 19) + P(X = 20) + P(X = 21) + P(X = 22) + P(X = 23) + P(X = 24) + P(X = 25)[/tex]
Then
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 18) = C_{25,18}.(0.8)^{18}.(0.2)^{7} = 0.1108[/tex]
[tex]P(X = 19) = C_{25,19}.(0.8)^{19}.(0.2)^{6} = 0.1633[/tex]
[tex]P(X = 20) = C_{25,20}.(0.8)^{20}.(0.2)^{5} = 0.1960[/tex]
[tex]P(X = 21) = C_{25,21}.(0.8)^{21}.(0.2)^{4} = 0.1867[/tex]
[tex]P(X = 22) = C_{25,22}.(0.8)^{22}.(0.2)^{3} = 0.1358[/tex]
[tex]P(X = 23) = C_{25,23}.(0.8)^{23}.(0.2)^{2} = 0.0708[/tex]
[tex]P(X = 24) = C_{25,24}.(0.8)^{24}.(0.2)^{1} = 0.0236[/tex]
[tex]P(X = 25) = C_{25,25}.(0.8)^{25}.(0.2)^{0} = 0.0038[/tex]
Then:
[tex]P(X > 17) = P(X = 18) + P(X = 19) + P(X = 20) + P(X = 21) + P(X = 22) + P(X = 23) + P(X = 24) + P(X = 25) = 0.1108 + 0.1633 + 0.1960 + 0.1867 + 0.1358 + 0.0708 + 0.0236 + 0.0038 = 0.8908[/tex]
0.8908 = 89.08% probability that more than 17 chips in the sample are good.
A similar problem is given at https://brainly.com/question/24863377
solve pls Brainliest
Answer:
25
Step-by-step explanation:
155-180=25 degrees
Answer:
x = 25°
Step-by-step explanation:
[tex]\frac { a } { ( a - b ) ( a - c ) } + \frac { b } { ( b - c ) ( b - a ) } + \frac { c } { ( c - a ) ( c - b ) }[/tex]
the formula is the question pleaseee helppp quickkk
Answer:
0
Step-by-step explanation:
[tex]\frac{a}{(a-b)(a-c)} +\frac{b}{(b-c)(b-a)}+\frac{c}{(c-a)(c-b)}\\= \frac{a}{(a-b)(a-c)} -\frac{b}{(b-c)(a-b)}+\frac{c}{(a-c)(b-c)}\\\\= \frac{a(b-c)-b(a-c)+c(a-b)}{(a-b)(a-c)(b-c)}}\\\\= \frac{ab-ac-ab+bc+ac-bc}{(a-b)(a-c)(b-c)}}\\\\= \frac{0}{(a-b)(a-c)(b-c)}}\\\\= 0[/tex]
Heyyyyyyyyyyyy can you help
Answer:
1.45 x 10 {2}
Step-by-step explanation:
covert 31 days into minutes
Answer:
MARK ME AS BRAINLIEST !!
Step-by-step explanation:
44640
Answer:
31 days =
44640 minutes
Step-by-step explanation:
Welcome
Three workers worked for 5 hours, 7 hours and 12 hours. The total wage of $
13200 was divided among the three workers according to the number of hours of
work they did. How much did each get?
Answer:
Worked 5 hours: $550
Worked 7 hours: $2,750
Worked 12 hours: $6,600
Step-by-step explanation:
5+7+12=24
13200/24 = 550
(5)*(550) = 2,750
(7)*(550) = 3,850
(12)*(550) = 6,600
Write the equation of the line, given the y and x-intercepts. a x-intercept = –68, y-intercept = –34
Answer:
In slope-intercept form, y = -17/34 - 34
Step-by-step explanation:
For the two points, you have (-68, 0) and (0, -34). To get the slope, you take (y-y) / (x-x). Stay consistent on the order you do those. After I did (-34 - 0) / (0 - 68), simplified it, and got a slope of -17 / 34. You are already given the y-intercept, so you just write the equation from there (y = -17/34 - 34)
Find the Value of x
Please answer!!
No links!!
Answer:
x = 15 inches
Step-by-step explanation:
[tex]a^{2} +b^{2} =c^{2} \\b^{2} = c^{2} - a^{2} \\b^{2} = (25 inches)^{2} - (40 inces/2)^{2} = \sqrt{225} = 15 inches[/tex]
Suppose there is a 1.2 drop in temperature for every thousand feet that an airplane climbs into the sky. If the temperature on the ground is 57.8, what will be the temperature when the plane reaches an altitude of 7000?
Answer:
ysgsvdbdbdjdnd dndjdnd
Using the graph of y = f(x) to the right, and given that the zero of the function is x=20, find the following.
Answer:
3.5
Step-by-step explanation:
Help!!!! Jack walked 3 1/3 miles in 4/3 hours. If he walked at a constant rate, how far did he walk in 15 minutes?
Answer: I think the answer is 0.625 miles.
Step-by-step explanation:in the picture
QUICK!!
fill in the blanks below in order to justify whether or not the mapping shown represents a function.
Step-by-step explanation:
I don't know what the specific options are to be selected, but I can tell you what the situation is, and you can then pick the fitting options on your screen :
it is not a function, because 5 in set A (the domain) leads to 2 associated (functional result) values in B (the range).
but in order to be a function, every input value must have exactly one resulting output value. which is violated here.
solve pls brainliest
Answer:
1) 2
2) 1
3) 8
Step-by-step explanation:
brainliest plz
Given g(x) = 2x + 5, find g(1).
Step-by-step explanation:
The value of g is already given. Replace g by 1 and find the value of x which is a negative two. After that, substitute and find that g is indeed equal to 1.
thankyou
Lillie is saving up for a trip she is taking with friends during her break from school. If Lillie's current monthly net pay is $429.00 and her monthly expenses are $347.49, what percent of her net pay is left for savings?
a
19%
b
23%
c
65%
d
81%
On Friday, 0.325 of the students in
Keisha's math class were absent. What
percent of the students were absent?
Look at picture for choices!! Quick!!
Andre wrote the expression -2 + 4x = 3 to represent the relationship shown in the table. Write two other expressions that also represent the relationship shown in the table.
Two other expressions that also represent the relationship shown in the table are;
4x-5 = 04x-5 = 0x = 5/4According to the question;
Andre wrote the expression -2 + 4x = 3 to represent the relationship shown in the tableIn essence, to write two other expressions that also represent the relationship shown in the table; we can rearrange the terms in the expression Andre wrote (-2 + 4x = 3) as follow;
First expression is;
-2 - 3 + 4x = 04x-5 = 0Second expression is;
4x = 5x = 5/4Read more:
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The lengths of the worms (in inches) are listed here.
Which line plot shows this data?
Answer:
Top Left
Step-by-step explanation:
The numbers all coordinate to that plot
Answer:
Plot #1Step-by-step explanation:
The easy way is to look for exceptions. The first and last plots missing 7/8 and same with data set.
There are 4 1's in the set which is correct with the first plot.
2. Louis kept losing money through a hole in his pocket. He started with 35€, lost 20€.
put in 754 more, spent 43¢ lost 16¢ again, and then put in 14¢. How much change should
there be in his pocket?
Your answer should be 724 cents, in dollars that is $7.24
Step-by-step explanation:
from the cents is shoes be 724 and the dollars souls be $7.24
5(Y-1)=3(2Y-5)-(1-3Y)
Answer: =11/4
Step-by-step explanation:
Answer:
[tex]y = 2 \frac{3}{4} \\ [/tex]
Step-by-step explanation:
[tex]5(y - 1) = 3(2y - 5) - (1 - 3y) \\ 5y - 5 = 6y - 15 - 1 + 3y \\ 5y - 5 = 9y - 16 \\ 16 - 5 = 9y - 5y \\ 11 = 4y \\ \frac{11}{4} = y \\ 2 \frac{3}{4} = y \\ [/tex]
Wooden flooring costs £35 per square metre. The floor is then edged with a narrow wooden strip which costs £4 per metre.
How much does it cost for a 6m by 4m room, including the edging?
Answer:
£920
Step-by-step explanation:
We need to find the area of floor to find the cost of the flooring, and then we need to find the perimeter of the floor to find the cost of the edging.
A = LW = 6 m × 4 m = 24 m²
Cost of flooring: 24 m² × £35/m² = £840
P = 2(L + W) = 2(6 m + 4m) = 2(10m) = 20 m
Cost of edging: 20 m × £4/m = £80
Total cost:
£840 + £80 = £920
direct variation
Hooke's Law for an elastic spring states that the distance a spring stretches varies directly as the force applied. if a force of 180 newtons stretches a spring 5 cm, how much will a force of 270 newtons stretch the same spring?
pls help (;ŏ﹏ŏ)
When a force of 270N is applied, the spring stretch by 7.5cm
Two variables are said to be directly proportional if as one variable increases/decreases, the other variables does the same by the same amount.
Let F represent the force and x represent the extension, hence:
F ∝ x
F = kx; k is the constant of proportionality
When F = 180, x = 5, hence:
180 = 5k
k = 36
F = 36x
When F = 270:
270 = 36x
x = 7.5 cm
When a force of 270N is applied, the spring stretch by 7.5cm
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Find the slope between these two points:
(4,7).(-6, -4)
Answer:
1.1
Step-by-step explanation:
slope = (-4-7)/(-6-4)= -11/-10 = 1.1
150 miles on 4 gallons of gas. How many miles for 1 gallon of gas?
Answer: answered
A motorcycle can go 50 miles using one gallon of gas. About how many gallons of gas will be used to go 150 kilometers? (Hint: 1 mile is approximately 1.6 kilometers)
Step-by-step explanation:
Answer:37.5
Step-by-step explanation:
You deposit $400 in an account earning 8% interest compounded annually. How much will you have in the account in 15 years?
Answer:
you will gain 280,462.92 in peso.but you convert in in dollar you will gain $5,520.00