1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Olin [163]
3 years ago
15

HELP.... please??????????????

Mathematics
1 answer:
Nostrana [21]3 years ago
8 0

Answers:

Functions

  • y = -x+11
  • y = 2x^2-6x+4
  • y = -7

Not functions

  • x = 3
  • x^2+y^2 = 81
  • y^2 = -5x-12

=======================================================

Explanation:

A function is possible if and only if any given x input leads to exactly one y output.

For something like x^2+y^2 = 81, we can see that x = 0 leads to either y = 9 or y = -9. So this would <u>not</u> be a function. We would need x to pair with only y value to have it be a function.

We have the same thing going on with y^2 = -5x-12 as well.

For anything of the form x = k, where k is any real number, this is also not a function. We have one single input only and it leads to infinitely many outputs. So in a sense, this is even worse compared to the other examples.

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

In summary, we have these three non-functions:

  • x = 3
  • x^2+y^2 = 81
  • y^2 = -5x-12

Everything else is a function. You can use the vertical line test as a visual way to check.

You might be interested in
Show tan(???? − ????) = tan(????)−tan(????) / 1+tan(????) tan(????)<br> .
anyanavicka [17]

Answer:

See the proof below

Step-by-step explanation:

For this case we need to proof the following identity:

tan(x-y) = \frac{tan(x) -tan(y)}{1+ tan(x) tan(y)}

We need to begin with the definition of tangent:

tan (x) =\frac{sin(x)}{cos(x)}

So we can replace into our formula and we got:

tan(x-y) = \frac{sin(x-y)}{cos(x-y)}   (1)

We have the following identities useful for this case:

sin(a-b) = sin(a) cos(b) - sin(b) cos(a)

cos(a-b) = cos(a) cos(b) + sin (a) sin(b)

If we apply the identities into our equation (1) we got:

tan(x-y) = \frac{sin(x) cos(y) - sin(y) cos(x)}{sin(x) sin(y) + cos(x) cos(y)}   (2)

Now we can divide the numerator and denominato from expression (2) by \frac{1}{cos(x) cos(y)} and we got this:

tan(x-y) = \frac{\frac{sin(x) cos(y)}{cos(x) cos(y)} - \frac{sin(y) cos(x)}{cos(x) cos(y)}}{\frac{sin(x) sin(y)}{cos(x) cos(y)} +\frac{cos(x) cos(y)}{cos(x) cos(y)}}

And simplifying we got:

tan(x-y) = \frac{tan(x) -tan(y)}{1+ tan(x) tan(y)}

And this identity is satisfied for all:

(x-y) \neq \frac{\pi}{2} +n\pi

8 0
3 years ago
The marketing club at school is opening a student store. They randomly survey 50 students about how much money they spend on lun
Luden [163]

Answer:

The expected value for a student to spend on lunch each day = $5.18

Step-by-step explanation:

Given the data:

Number of students______$ spent

2 students______________$10

1 student________________$8

12 students______________$6

23 students______________$5

8 students_______________$4

4 students_______________$3

Sample size, n = 50.

Let's first find the value on each amount spent with the formula:

\frac{num. of students}{sample size} * dollar spent

Therefore,

For $10:

\frac{2}{50} * 10 = 0.4

For $8:

\frac{1}{50} * 8 = 0.16 l

For $6:

\frac{12}{50} * 6 = 1.44

For $5:

\frac{23}{50} * 5 = 2.3

For $4:

\frac{8}{50} * 4 = 0.64

For $3:

\frac{4}{50} * 3 = 0.24

To find the expected value a student spends on lunch each day, let's add all the values together.

Expected value =

$0.4 + $0.16 + 1.44 +$2.3 + $0.64 + $0.24

= $5.18

Therefore, the expected value for a student to spend on lunch each day is $5.18

7 0
3 years ago
Can someone help me please?
jeka57 [31]

Answer:

This is the graph of the question

Step-by-step explanation:

8 0
3 years ago
Which expression represents 7 less than the product of 11 and 4 .
ryzh [129]
The answer is (4x11)-7 i believe
3 0
3 years ago
What is the estimate of 137,638 plus 52,091
polet [3.4K]
The answer is 189,729
If to be rounded answer would be 190,000 I would say best estimate would be 180,000
3 0
3 years ago
Read 2 more answers
Other questions:
  • Which expressions are correct for the situation?
    10·2 answers
  • If Darnell can buy 10 cases of water for $30.00, how much would it cost for 15 cases
    10·1 answer
  • about 50 percent of the population of Alaska lives within a 50 mile radius of Anchorage if the total area of Alaska is 580 6412
    9·1 answer
  • If the eccentricity of an ellipse is 0.43 and the length of its major axis is 11 units, how far from the center are the foci loc
    14·2 answers
  • Write the standard form of the equation of the circle with its center at (-5,0) and a radius of 8 what is the equation of the ci
    12·1 answer
  • A bag is filled with 4 red marbles, 3 blue marbles, 3 yellow marbles, and
    5·1 answer
  • Cassandra earns $12.98 an hour working at Key Food. How much money will she
    13·1 answer
  • Ahh can someone please help me
    13·1 answer
  • Express (81^1/4)^3<br> in simplest radical form.
    10·1 answer
  • On Tuesday Emily bought four posters,
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!