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
lys-0071 [83]
3 years ago
5

Is -√15 an imaginary or irrational number?

Mathematics
2 answers:
Leno4ka [110]3 years ago
7 0

Hey there! I'm happy to help!

An irrational number is a real number that can't be written as a ratio of two other integers (non-fraction numbers) so a number like π or √2.

An imaginary number is one that breaks a mathematical rule so it can't necessarily exist as a real number. The main imaginary number is <em>i, </em>and here is the thing it does that breaks the rules and makes it imaginary:

<em>i</em>²=-1

so

√-1=<em>i </em>

We know that you cannot square a real number and have it be negative because a negative number can only be obtained by multiplying a positive and a negative number. This also shows us that there cannot be a square root of a negative number.

We have the number -√15. The placement of that negative sign is CRUCIAL! The square root of any positive integer is going to be a real number, but the square root of a negative number is nonexistent aka imaginary. √-15 would be an imaginary number, but we have -√15, which is the same thing as -1·√15. The negative sign is not inside the square root, which makes it not imaginary, so this is an irrational number. You can plug it into a calculator and it would be -3.872983346....

Have a wonderful day and keep on learning :)

Kazeer [188]3 years ago
6 0

Answer:

irrational

\sqrt{-15} would be imaginary

Step-by-step explanation:

You might be interested in
Find the solutions to x2 = 20.
aev [14]
A. would your best answer....hope this helps.
6 0
3 years ago
Read 2 more answers
I need help on this. Please
serious [3.7K]

Answer: choice C, y = 0.014x+0.85

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

Explanation:

Each column of the table represents an (x,y) pair of values

x = number of pages

y = cost

If we look at the first two columns, we see the two points (50,1.55) and (100,2.25). The x value is listed first. Let's compute the slope of the line through these two points

m = (y2-y1)/(x2-x1)

m = (2.25-1.55)/(100-50)

m = 0.7/50

m = 0.014

So far, we see the answer is between A,B or C as they have the slope of 0.014

Use this slope value, and one of the points -- say (x,y) = (50,1.55) -- to find the y intercept b

y = mx+b

y = 0.014x+b .... plug in the slope found earlier

1.55 = 0.014*50+b ... plug in the point (x,y) = (50,1.55)

1.55 = 0.7+b

1.55-0.7 = 0.7+b-0.7 ... subtract 0.7 from both sides

0.85 = b

b = 0.85

With m = 0.014 as the slope and b = 0.85 as the y intercept, we can say that y = mx+b turns into y = 0.014x+0.85. That narrows the answer down to choice C.

3 0
3 years ago
What is the radius of a circle what circumference is 44cm
LuckyWell [14K]

Hello!!

Circumference of a circle = 2πr

and

Given, 2πr = 44cm

So,

πr = 44/2 = 22

r = 22 × 7/22

r = 7cm is the answer.

Stay safe and God bless!

- eli <3

8 0
3 years ago
Read 2 more answers
Answer the question in the picture
Svet_ta [14]
<h3>Answer:</h3>
  • left picture (bottom expression): -cot(x)
  • right picture (top expression): tan(x)
<h3>Step-by-step explanation:</h3>

A graphing calculator can show you a graph of each expression, which you can compare to the offered choices.

_____

You can make use of the relations ...

... sin(a)+sin(b) = 2sin((a+b)/2)cos((a-b)/2)

... cos(a)+cos(b) = 2cos((a+b)/2)cos((a-b)/2)

... cos(a)-cos(b) = -2sin((a+b)/2)sin((a-b)/2)

Then you have ...

\dfrac{\cos{2x}-\cos{4x}}{\sin{2x}+\sin{4x}}=\dfrac{2\sin{3x}\sin{x}}{2\sin{3x}\cos{x}}=\dfrac{\sin{x}}{\cos{x}}=\tan{x}

and ...

\dfrac{\cos{2x}+\cos{4x}}{\sin{2x}-\sin{4x}}=\dfrac{2\cos{3x}\cos{x}}{-2\cos{3x}\sin{x}}=\dfrac{-\cos{x}}{\sin{x}}=-\cot{x}


6 0
3 years ago
Can someone help me with this. Will Mark brainliest . Need answer and work/explanation. Thank you.
Rom4ik [11]

Answer:

Hope it helps...

Step-by-step explanation:

5 0
2 years ago
Other questions:
  • The line that best models the data shown on the scatterplot is line?<br> A. <br>B. <br>C.<br>D. ​
    13·2 answers
  • FIND AREA ASAP PLEASE
    6·1 answer
  • Which would be a correct first step to solve the following system of linear equations using the elimination method? 2x+3y=6
    15·1 answer
  • Nate solves the problem 3x5=15 by writing and solving 15 divide 5=3. explain why nates method works
    9·1 answer
  • 2(x-4)+3=7 which of these is x 4,6,7,8
    14·2 answers
  • 6 There are 10 lanes in the bowling alley where Harold bowls. He wants to make a
    6·1 answer
  • Which set of ordered pairs (x, y) could represent a linear function?
    5·1 answer
  • Solve the inequality below. -18 x<br> -7 &gt; x<br> 7 &lt; x<br> -7 &lt; x
    5·1 answer
  • 3,411-234 3. Please answer fast I need it now<br>​
    5·1 answer
  • PLS HELP, EXPLANATION IS GREATLY APPRECIATED!!!!!
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!