Spyke
lemmy.ml

What about plain old x = -10?

-10 ^ 2 = 100
-10 ^ 3 = -1000
-10 ^ 5 = -100000

169
pr06lefsreply
lemmy.ml

people being pedantic showoffs doesn't really register as humor for me, TBH

35

That's true, the OOP is being quite snarky with their comment on a post where someone's had a genuine basic doubt

12
programming.dev

When all you have is an imaginary hammer, everything looks like a rotation around the imaginary unit circle.

::: spoiler Explanation of maths x = -10, i = √-1 so i² = -1 and 10i²=-10 :::

96
feddit.cl

The square root is always positive, but you can plug it into the quadratic formula to get the two possible values.

-3

Seems very inaccurate the we can only determine the square root to +-10.

1

There's no reason to bring the quadratic formula into this. Square roots can be negative, but when talking about the square root it's normally assumed to be the principal square root, which is the positive one.

8

Nope. To clarify, square roots are the opposite of squaring.

Now ask yourself:

What is 10² ?

What is (-10)² ?

If you get the same answer, then they are both the roots of the answer. +10 and -10 then gets together called ±10

1
Cryophiliareply
lemmy.world

That's because the explanation was about 10 times as complicated as it needs to be

44
feddit.org

No definition what values are suitable for x.

10
quicksandreply
lemm.ee

x has to be -10, right? Or am I missing something?

20
jacksilverreply
lemmy.world

Yeah, I think the point is that the person answering was wrong/over complicating. If x=10i, then x^2 would be -100 (or potentially -10 depending on what you think the ^2 is applied to).

6

They said x=10i^2, not 10i. Difference is it equals -10, and they chose not to simplify.

22

They're correct, it's just overcomplicated as fuck in ways that are correct but completely irrelevant to the question.

4

Depends on what are the allowed values for x are. Real numbers, complexe numbers, binary or I made up my own numbers ;)

4
lemm.ee

What an extremely unnecessary explanation. As a math teacher I would have deducted points for this answer.

9

Unless I was in that clas where we had to write mathematical proofs. I HATED those. Sure, you solved the question but write out this complicated reason for why your answer is the correct answer.

1

You reached the end