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
Digiron [165]
3 years ago
15

Find the domain of f(x)=x-9/x squared-81

Mathematics
1 answer:
vagabundo [1.1K]3 years ago
7 0

f(x)=\dfrac{x-9}{x^2-81}\\\\\text{The domain:}\\\\x^2-81\neq0\qquad\text{add 81 to both sides}\\\\x^2\neq81\to x\neq\pm\sqrt{81}\\\\x\neq-9\ \wedge\ x\neq9\\\\Answer:\ \boxed{\text{All real numbers except -9 and 9}}\to\boxed{x\in\mathbb{R}-\{-9,\ 9\}}

You might be interested in
Which of the following estimates at a 95% confidence level most likely comes from a small sample?
dusya [7]
<span>The <u>correct answer</u> is:

A) 60% ± 18%.

Explanation:

In a confidence interval, the margin of error is given by z*(</span>σ/√n<span>), where </span>σ<span> is the standard deviation and n is the sample size.

First we <u>find the value of z</u>:

We want a 95% confidence level; 95% = 95/100 = 0.95.

To find the z-score, we first subtract this from 1:
1-0.95 = 0.05.

Divide by 2:
0.05/2 = 0.025.

Subtract from 1 again:
1-0.025 = 0.975.

Using a z-table, we find this value in the middle of the table. The z-score that is associated with this value is 1.96.

Back to our formula for margin of error, we have 1.96(</span>σ<span>/</span>√n<span>). The larger n, the sample size, is, the larger its square root is. When we divide by a larger number, our answer is smaller; this gives us a smaller margin of error.

This means that if we had a small sample size, we would divide by a smaller number, making our margin of error larger. The largest margin of error we have in this question is 18%, so this is our correct answer.</span>
7 0
3 years ago
Select the polynomial that is a perfect square trinomial.
alexdok [17]

Answer:

Option D. It's a perfect square trinomial.

Step-by-step explanation:

(a) 36x² - 4x + 16

= (6x)² - 2(2x) + (4)²

It's not a perfect square trinomial

(b) 16x² - 8x + 36

= (4x)² - 2x(4x) + (6)²

It's not a perfect square trinomial

(c) 25x² + 9x + 4

= (5x)² + 2(\frac{9}{2}x) + (2)²

It's not a perfect square trinomial

(d) 4x² + 20x + 25

= (2x)² + 2(10x) + (5)²

= (2x+5)²

It's a perfect square trinomial.

8 0
3 years ago
Read 2 more answers
12c+2d=48g solve for d
Lostsunrise [7]

Answer:

d=−6c+24g

Step-by-step explanation:

6 0
3 years ago
Read 2 more answers
Josue bought seven boxes. A week later half of all his boxes were destroyed in a fire.
fgiga [73]

Answer:

he started with 44 boxes

6 0
3 years ago
If you have 35 books and you order 320% more books. How many books will you have in total?
Olegator [25]

Answer:

You would have 147 books

Step-by-step explanation:

Doge is smart, he has big brain.

Doge used a calculator

7 0
2 years ago
Other questions:
  • Someone help me plsh
    11·1 answer
  • What shapes have only 1 pair of opposite sides parallel?
    14·2 answers
  • MZRSK = x + 53, m KST = x + 109,<br> and mZRST = 156º<br><br><br> Find x.
    9·1 answer
  • D+f=4gb solve for b pleaseeee answer
    13·2 answers
  • Which of the following is the third value for the data set below
    7·1 answer
  • Identify the exponent in the following number: 2^5<br> A. 2<br> B. 5<br> C. 16<br> D. 32
    15·1 answer
  • Using mixed numbers, write a problem in which an estimate is enough to solve the problem.​
    5·1 answer
  • The_______determines the scale of the scale of the coordinate plans.
    13·1 answer
  • Y=x^2+6x-72 write the equation in vertex form
    11·1 answer
  • Nada drives her car at an average speed of 60 miles per hour. She is planning a drive between 150 and 180 miles. Write and solve
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!