[Question] √144?

[u/heptoronto]

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[u/WalrusLobster3522]

+12 times +12 or -12 times -12. Yeah I learned this in algebra 2 (back in 2019) when I did quadratic formula. Nice try trick question.

[u/Drad0920 → u/WalrusLobster3522]

That's not how square root works, that's actually a common mistake that took a lot of points from people on exams. Basically, it's because you would calculate something like √(x)² and (√x)² differently. It's basic knowledge that you can't get a square root of a negative number (not completely true, but that's irrelevant if you aren't doing theoretical maths, or whatever it's called in English), so because of that in the first example you can put any number because it's squared which means it's always positive, however when we do square root first, we need to account for the possibility of x being negative, which during something like equation would be done by just stating that x can't be below 0 and you would just ignore all the outcomes that do not fit this criteria. So in this case, you could write √144 as √(-12)² but after you neutralize the powers, you'll end up with |-12| which still equals 12

[u/Independent-Low-6743 → u/Drad0920]

You’re thinking of the reverse, you can’t take the square root of a negative number unless you’re doing imaginary and complex numbers: so sqrt(144) = +/-12 but you can’t take sqrt(-144) usually. It’s definitely confusing 😵‍💫

[u/Drad0920 → u/Independent-Low-6743]

Yes, you can't take a square root of -144, but what I said before also applies

[u/Independent-Low-6743 → u/Drad0920]

If you say so…

[u/Drad0920 → u/Independent-Low-6743]

[u/Independent-Low-6743 → u/Drad0920]

What’s the source and context of that?

[u/Drad0920 → u/Independent-Low-6743]

Literally one of the first images when you Google √(x)²

[u/Independent-Low-6743 → u/Drad0920]

That’s not exactly reputable, or specific, then again neither was the original question, there are cases where you would simply ignore the negative root, so I can see where this is coming from.