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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Use the Quadratic Formula to solve for x and then determine whether your solution is real or
complex.
y = x2 - 4x + 9
**Remember y = 0**
O Real
o Complex
Answer:
[tex] {x}^{2} - 4x + 9 = 0 \\ x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} \\ x=\frac{-( - 4)\pm\sqrt{( - 4)^2-4(1)(9)}}{2(1)} \\x=\frac{ 4\pm\sqrt{ 16-36}}{2} \\ x=\frac{ 4\pm\sqrt{ - 20}}{2} \\ x=\frac{ 4\pm2i\sqrt{ 5}}{2} \\ x = 2\pm \: i\sqrt{ 5} \\ D = {b^2-4ac} \\D = { 16-36} \\ = - 20 < 0 \rightarrow \: x \in \: \mathbb{C} \: \\ x \: is \: complex [/tex]
7. The ratio of the base to height of a triangle is 3:5. If the area of this triangle is 30, find the lengths of the base and height.
Answer:
Base= 6
Height= 10
Step-by-step explanation:
Area of triangle= ½ ×base ×height
Let the base be 3x and the height be 5x.
Given that the area is 30,
½ ×base ×height= 30
½(3x)(5x)= 30
Multiply both sides by 2:
3x(5x)= 60
15x²= 60
x²= 60 ÷15
x²= 4
Square root both sides:
[tex]x = \sqrt{4} [/tex]
x= 2
(reject x= -2 since length has a positive value)
Length of base
= 3x
= 3(2)
= 6
Length of height
= 5x
= 5(2)
= 10
3 to the power of 1/7
Answer: 0.42857142857
Step-by-step explanation:
needing help with fraction problem
4/11 - 10/8 equals?
having trouble breaking it down to get the answer
Answer:
71/44
Step-by-step explanation:
Here the LCD is the product of the two denominators given: 11*8 = 88.
We rewrite 4/11 as 32/88 and 10/8 as 110/88. Now the denominators are the same.
Combine 32/88 and 110/88. We get the sum 142/88, which reduces to 71/44.
Answer:
-39/44.
Step-by-step explanation:
We need to find the lowest common multiple of 11 and 8.
This is 88.
Now to convert the 2 fractions to denominator 88 we multiply first by
8/8 and the second by 11/11:
4/11 - 10/8
= 32/88 - 110/88
= -78/88
= -39/44
Pleas help me out here.
Answer:
A and E
Step-by-step explanation:
The given problem shows a graph of a vertical line with an undefined slope, in which its equation is x = 3 (which matches Option A).
It is not considered a function because it has the same input for every given output. This means that regardless of its y-coordinate, its corresponding x-coordinate will always be x = 3.
The Vertical Line Test allows us to know whether or not a graph is actually a function. Remember that a function can only take on one output for each input. We cannot plug in a value and produce two output values. Since the graph represents a vertical line, it automatically fails the vertical line test. Therefore, it is not a function.
Because it is not a function, Options B, C, and D are invalid answers.
Hence, the correct answers are Options A and E.
758 rounded of to the nearest hundred
Answer:
800
Step-by-step explanation:
Hope this helps
Answer:
800, if it's higher than 50 you can round it to the next hundred
Can someone please help me on this problem I’m struggling
Answer:
No pictures so can't help ya.
Estimate and then solve 6,699 ÷ 72 = ___.
92 r 4
93 r 3
93 r 4
94 r 3
Answer:
It would be 93 remainder 3/the second one.
right please no link or bot
Answer:
3^18
Step-by-step explanation:
Hope it helps
Answer:
3^3
Step-by-step explanation:
the 10th term of an arithmetic sequence is 57 and the seventh term is 447 find the common difference and the first term
Answer:
232
Step-by-step explanation:
In a group of 97 students, the number of students taking programming is twice the number of students taking math. There are 53 students taking exactly one of these subjects, and 15 are taking neither of these subjects. How many students are taking math? How many students are taking programming? In a group of 97 students, the number of students taking programming is twice the number of students taking math. There are 53 students taking exactly one of these subjects, and 15 are taking neither of these subjects. How many students are taking math? How many students are taking programming?
The number of student taking math is 37 while the number of students taking programming is 74
Universal set = 97
let
The number taking math = x
The number taking programming = 2x
The number of students that take exactly one subject = 53
The student taking neither of the subject = 15
The number of students taking only maths will be
x - n(m ∩ p)The number of students taking only programming will be
2x - n(m ∩ p)let
n(m ∩ p) = y
Therefore,
x - y + 2x - y = 53
3x - 2y = 53
Also,
97 = x + 2x - y + 15
3x - y = 82
Therefore,
3x - 2y = 53
3x - y = 82
-y -(-2y) = 82 - 53
y = 29
3x - 29 = 82
3x = 82 + 29
3x = 111
x = 111/3
x = 37
Finally,
number of students taking maths = 37
number of student taking programming = 37×2 = 74
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Use the graph below to find the indicated expression: f(3)-f(-3)
Answer:
f×3-f×(-3)
3f+3f
solution:
6f
Step-by-step explanation:
hope it's can help
A baker packed 24 cupcakes into each box. After he had packed 37 boxes of cupcakes, there were 248 cupcakes left. How many cupcakes were there altogether?
Hope this helps have a great day!!!!!
Sorry its blurry but please hurry!!!!!!! Answer 9 and 10 please!!!!
Answer:
9. 31/2 or 15.5( I think that's the answer)
10. B
Step-by-step explanation:
A number that has more than two factors is a
Composite number? I’m not sure if that’s what you’re working on but it’s a true statement.
I think of a number Then multiply it by 3 then add 4 then divide by 4 my final answer is 3 less than the number is the number i thought of the beginning.
Write it as an equation and solve.
Find the circumference of a circle with a radius of 7 centimeters. Use 3.14 as an approximation for pi . Round your answer to the nearest whole centimeter. Enter only the number.
Hi this is the answer and explaination
I'm sorry if it's incorrect
hope's it's help
The circumcenter of a circle with a radius of 7 cm is, 44cm.
What is circumference?Circumference is the distance around the perimeter of a circular object. It is defined as the length of the circle that is found by multiplying the diameter of the circle by π (pi), which is approximately equal to 3.14.
The formula for the circumference of a circle is given by: C = 2πr,
Given that,
The radius of circle = 7 cm
Substituting the given value of radius as 7 and using pi = 3.14,
we get:
Circumference = 2 × 3.14 × 7
= 43.96
Rounding this to the nearest whole centimeter, we get:
Circumference ≈ 44
Therefore, the circumference of the circle with a radius of 7 centimeters is approximately 44 centimeters.
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How many combinations are possible? Assume the items are distinct.
10 items chosen 10 at a time
a 2) Choose the correct name for the set of numbers. . {4 4. 256, 0.888, 26, – 4.0, 81 1.0, 781 4 O natural numbers O irrational numbers integers O whole numbers real numbers O rational numbers
Answer:
irrational numbers integers
The lines graphed below are parallel. The slope of the red line is - What is
.
the slope of the green line?
X
-5
5
m =
O A. -
ОВ.
Rlო
4
3
O c. -
O c c
O D.
O
3
4
Answer:
C. -4/3
Step-by-step explanation:
Parallel lines have the same gradient (steepness) and this means that they will never intersect.
Hope this helps!
The slope of the red line will be {m} = - 4/3.
What is the general equation of a straight line?The general equation of a straight line is -
y = mx + c
where -
{m} is the slope of the line.
{c} is the {y} - intercept.
Given is that the straight lines graphed below are parallel.
The slope of the red line could be calculated from the points through which the line passes. The points are : (- 3, 0) and (0, 4).
{m} = (- 4 - 0)/(0 + 3)
{m} = - 4/3
Since the lines are parallel, we can write the slope of the green line as same as that of the red line.
Therefore, the slope of the red line will be {m} = - 4/3.
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PLS HURRY WILL GIVE BRAINLIEST & 20 PTSS!!!!
Answer:
(0,2) x (3,-2)
Step-by-step explanation:
Homework help!!!!!!!
Answer:
r = -9
Step-by-step explanation:
the less the negative number is the more it is .
Write an equation of the line in slope-intercept form. JY 1 (3, 3) (0, 2) 2 4
y=
Correct answer: y = [tex]\frac{1}{3}[/tex]x + 2
To find out the slope, you would need to remember this slope formula: [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]. We can use the two points provided on the graph to figure out the slope. We can label (3, 3) as [tex]x_{1}[/tex] and [tex]y_{1}[/tex], and (0, 2) as [tex]x_{2}[/tex] and [tex]y_{2}[/tex]. Now we can plug these numbers into the slope formula to find out the slope:
m = [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex] → [tex]\frac{2-3}{0-3}[/tex] → [tex]\frac{-1}{-3}[/tex] → [tex]\frac{1}{3}[/tex]
To find out the y-intercept, just substitute (3, 3) into the slope-intercept formula ( y = mx + b ) with the slope that is substituted for 'm' that we already solved earlier.
y = mx + b
(3) = [tex]\frac{1}{3}[/tex](3) + b
3 = 1 + b
2 = b
You can also prove this true by looking at the graph provided. The line intersects at the y-axis at 2.
Now we know that m = [tex]\frac{1}{3}[/tex] and b = 2, we can substitute it into the slope-intercept formula. Thus, the answer is y = [tex]\frac{1}{3}[/tex]x + 2.
Hope this helps you! Let me know if you have any more questions related to this problem.
What is the opposite of V3?
i will give brainliest to the best answer.
Answer:
Step-by-step explanation:
The slope intercept form is like so:
y = mx + b
mx is the slope
b is the y-intercept
Now in your equation:
y = 0.25x + 2
0.25x is the slope
2 is the y-intercept
I need it asap fast and I give brainliest to a right answer.
Answer:
hiik
Step-by-step explanation:
rvnlgsudffstdrestdftuisffjhigyhoffyxhcccdfidsudjifg
what is the length of segment XZ?
192
12
8
144
Answer:
12 is the length of XZStep-by-step explanation:
Pythagorean Theorem Formula: a² + b² = hypotenuse²
x² + 5² = 13²
x² + 25 = 169
x² + 25 - 25 = 169 - 25 (subtract 25 in both sides)
x² = 169 - 25
√x² = √144
x = 12
2. In our country today, what do you think are the possible application of pattern and sequence in the field of engineering? How?
Engineering has many applications in our country focused on the construction and development of new technological devices.
Engineering is a term that refers to the set of scientific principles necessary to design and build machines, structures, and others such as:
BridgesTunnelsRoadsVehiclesBuildingsSystemsProcesses.Engineering is characterized by:
Innovation and invention.Development and improvement of techniques and instruments.According to the above, engineering has many applications in the country such as:
Construction of new and more technological buildingsManufacture of tools and devices for different applications such as education, medicine, construction, among others.Learn more in: https://brainly.com/question/18564178
Helpppppppp meeeeeeee
Answer:
Step-by-step explanation:
solution 1:
570 not man = 15% (cause 100% - 85%)
15% = 570
100% = w (for "whole package")
15w = 100 * 570
15w = 57000
w = 57000 / 15
w = 3800
solution 2:
15% = 570
85 = m (for "men)
15m = 570 * 85
15m = 48450
m = 48450 / 15
m = 3230
100% = 85% + 15%
100% = b (for "buch of people")
b = 3230 + 570
b = 3800
What single percentage change is equivalent to a 14% increase followed by a 11% decrease?
Options:
4.54% decrease
26.54% increase
4.54% increase
1.46% decrease
26.54% decrease
1.46% increase
Answer:
1.46%
Step-by-step explanation:
Pretend you have a number as a test dummy. We'll go with 100 for simplicity. A 14% increase to 100 would be 114. Then we can decrease 114 by 11%. We can find 11% of 114 with an equation like so: x/114 = 11/100. We can then cross multiply to get this" 100x = 1254, which can be simplified to x=12.54. Now, we can subtract 12.54 from 114, which will get us 101.46. Because percentage is based on 100, we can simply subtract 100 from 101.46, which gives us 1.46. So, the answer is 1.46%.