I need help please?!!

Use complete sentences to describe why √-1 ≠ -√1

tekilochka [14]

Well let's say that to compare these two numbers, we have to start with the definition first.

Definition

$\displaystyle \large{ {y}^{2} = x} \\ \displaystyle \large{ y = \pm \sqrt{x} }$

Looks like we can use any x-values right? Nope.

The value of x only applies to any positive real numbers for one reason.

As we know, any numbers time itself will result in positive. No matter the negative or positive.

Definition II

$\displaystyle \large{ {a}^{2} = a \times a = |b| }$

Where b is the result from a×a. Let's see an example.

Examples

$\displaystyle \large{ {2}^{2} = 2 \times 2 = 4} \\ \displaystyle \large{ {( - 2)}^{2} = ( - 2) \times ( - 2) = | - 4| = 4}$

So basically, their counterpart or opposite still gives same value.

Then you may have a question, where does √-1 come from?

It comes from this equation:

$\displaystyle \large{ {y}^{2} = - 1}$

When we solve the quadratic equation in this like form, we square both sides to get rid of the square.

$\displaystyle \large{ \sqrt{ {y}^{2} } = \sqrt{ - 1} }$

Then where does plus-minus come from? It comes from one of Absolute Value propety.

Absolute Value Property I

$\displaystyle \large{ \sqrt{ {x}^{2} } = |x| }$

Solving absolute value always gives the plus-minus. Therefore...

$\displaystyle \large{ y = \pm \sqrt{ - 1} }$

Then we have the square root of -1 in negative and positive. But something is not right.

As I said, any numbers time itself of numbers squared will only result in positive. So how does the equation of y^2 = -1 make sense? Simple, it doesn't.

Because why would any numbers squared result in negative? Therefore, √-1 does not exist in a real number system.

Then we have another number which is -√1. This one is simple.

It is one of the solution from the equation y^2 = 1.

$\displaystyle \large{ {y}^{2} = 1} \\ \displaystyle \large{ \sqrt{ {y}^{2} } = \sqrt{1} } \\ \displaystyle \large{ y = \pm \sqrt{1} }$

We ignore the +√1 but focus on -√1 instead. Of course, we know that numbers squared itself will result in positive. Since 1 is positive then we can say that these solutions exist in real number.

Conclusion

So what is the different? The different between two numbers is that √-1 does not exist in a real number system since any squared numbers only result in positive while -√1 is one of the solution from y^2 = 1 and exists in a real number system.

5 0

2 years ago

Read 2 more answers

A scientist has started a bacteria culture with 1,000 cells. The cells will double every hour. 1. Write the sequence that repres

babymother [125]

Answer:

See below in bold.

Step-by-step explanation:

1. The sequence is 1000, 2000, 4000, 8000.

2. The common ratio is 2000/1000 = 2.

3. Number of bacteria after 7 hours is 1000(2)^(7- 1)

= 64,000.

4. 1000(2)^(x-1) > 1,000,000

2^x-1 > 1000

x- 1 log 2 > log 10

x- 1 > 9.96

x > 10.96

During the 11th hour.

8 0

3 years ago

Sarah made $180 for 12 hours of work. At the same rate, how much would he make for 17 hours of work?

lisabon 2012 [21]

Answer:

1260

Step-by-step explanation:

180 x 2

8 0

3 years ago

25 x 1/10 write in simplest form. Identify the two whole number between which the product lies

Margaret [11]

Answer:

25× 1/10 = 5/2

Step-by-step explanation:

5/2 or 2.5 lies between 2 and 3

4 0

2 years ago

Which expression represents a factorization of 16a - 24ab

Marizza181 [45]

I would choose A

You can simply try every answer and see which one gives you 16a-24ab

4 0

2 years ago