SmartmanApps

(-3)²

Well, in my defense, that’s has the uglies.

Well, the alternative is to have to write -(3)² every time to show it's not (-3)², so pick your poison.

You do the exponent first, then multiplication.

-3² = -1 * 3²

There's no multiplication, just subtraction (from an unwritten 0). -3² = 0-3²

there is no space to indicate the - represents a subtraction operator

Spaces don't mean anything in Maths, and I don't know why people keep adding them in! A minus sign is a minus sign, whether there are spaces next to it or not.

the immediate prefix - actually represents: (-1)x

No, it actually doesn't. It represents 0-x. Every operation on the number line starts from 0.

this actually represents (-1)(x²)

No, it actually represents 0-x²

such that PEMDAS is upheld

Which what you wrote doesn't. M refers literally to Multiplication signs. S refers literally to subtraction signs. -x² is E then S in PEMDAS.

I don’t make these rules

You did make those up actually (or you've repeated someone else who made them up).

but this is how it works

No it isn't. A minus sign is the S in PEMDAS, not M.

Double check in wolfram alpha if you doubt it

Look in a Maths textbook. Wolfram is known to be wrong in several areas. University professors warn their students against using it without adding brackets everywhere.

there’s a difference between - as an infix operator (10 - 5) and - as a prefix (-3).

The only difference is whether it's in brackets or not. To square the number -3 you need to put it in brackets, otherwise you're only squaring 3.

x2 where x = -3, I don’t think you’d say it’s -9

That's because anytime you substitute for a pronumeral, whatever the pronumeral represents goes in brackets. e.g. for x=3, 2x=2(3). So if x=-3, then x²=(-3)², as opposed to if x=3, we have -x²=-(3)². Whatever the pronumeral is equal to is inside brackets when you substitute.

Surely that would mean the answer’s ambiguous, no?

No. Exponents before Subtraction. Order of operations rules.

The lack of brackets means we can’t know definitively if - is included or not

The lack of brackets mean we definitively do know that it's not included, because to be included, it would have to be in brackets.

I’d argue that -3 represents negative three, not subtract three

It's actually 0-3. There's an unwritten 0, just like if the first number was positive there's an unwritten +. 9 is actually 0+9. All operations on the number line start from 0.

negative three is it’s own distinct number from positive three

"positive 3" is actually 0+3.

I usually skip [reading] them

Me too.

the map is 2 communities short

Couldn't find 2 hidden communities? I guess it's working then! 😂

Why post something that isn’t even out for another 10 days?

Because some might want to watch it live and participate in the chat.

I do agree that per dev is such a weird way to do licensing.

Related - I was teaching at a school where I wanted them to get some plagiarism tool. The charge was per student. It was a newish school with a lot of growth, and another new school was still being built nearby (not being put into service for another year or two), so the school had A LOT of students (nearly 2 school's worth), so, they couldn't afford it. I ended up having to manually copy some of my student's code and then Google it to see if they had copied it from anywhere (and yes, some of them had. BTW the most hilarious poor effort at trying to cheat was one who's code not only didn't even compile, but they hadn't even bothered changing the Imperial measurements to Metric! Didn't even need to Google that one - here's your letter to parents 😂).

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