this post was submitted on 03 Dec 2023
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BEDMAS: Bracket - Exponent - Divide - Multiply - Add - Subtract
PEMDAS: Parenthesis - Exponent - Multiply - Divide - Add - Subtract
Firstly, don't forget exponents come before multiply/divide. More importantly, neither defines wether implied multiplication is a multiply/divide operation or a bracketed operation.
The Distributive Law says it's a bracketed operation. To be precise "expand and simplify". i.e. a(b+c)=(ab+ac).
Exponents should be the first thing right? Or are we talking the brackets in exponents..
Exponents are second, parentheses/brackets are always first. What order you do your exponents in is another ambiguity though.
No it isn't - top down.
2^3^4 is ambiguous. 2^(3^4) is standard practice, but some calculators aren't that smart and will do (2^3)^4.
It's ambiguous because it works both ways, not because we don't have a standard. Confusion is possible.
The only confusion I can see is if you intended for the 4 to be an exponent of the 3 and didn't know how to do that inline, or if you did actually intend for the 4 to be a separate numeral in the same term? And I'm confused because you haven't used inline notation in a place that doesn't support exponents of exponents without using inline notation (or a screenshot of it).
As written, which inline would be written as (2^3)4, then it's 32. If you intended for the 4 to be an exponent, which would be written inline as 2^3^4, then it's 2^81 (which is equal to whatever that is equal to - my calculator batteries are nearly dead).
We do have a standard, and I told you what it was. The only confusion here is whether you didn't know how to write that inline or not.
Try reading the whole sentence. There is a standard, I'm not claiming there isn't. Confusion exists because operating against the standard doesn't immediately break everything like ignoring brackets would.
Just to make sure we're on the same page (because different clients render text differently, more ambiguous standards...), what does this text say?
It should say
2^3^4; "Two to the power of three to the power of four". The proper answer is 2⁸¹, but many math interpreters (including Excel, MATLAB, and many students) will instead compute 8⁴, which is quite different.We have a standard because it's ambiguous. If there was only one way to do it, we'd just do that, no standard needed. You'd need to go pretty deep into kettle math or group theory to find atypical addition for example.
Ah ok. Sorry, got caught out by a double negative in your sentence.
Ah but that's exactly the original issue in this thread - the e-calc is ignoring the rules pertaining to brackets. i.e. The Distributive Law.
Ah ok. Well that was my only confusion was what you had actually intended to write, not how to interpret it (depending on what you had intended). Yes should be interpreted 2^81.
Yeah, but Excel won't let you put in a factorised term either. It's just severely broken because the people who wrote it didn't bother checking the rules of Maths first. Programmers not knowing the rules of Maths doesn't mean Maths is ambiguous (it certainly creates a lot of confusion though!).
Disagree. There is one way to do it - follow the rules of Maths. That's why they exist. The order of operations rules are at least 400 years old, and make it not ambiguous. If people aren't obeying the rules then they're just wrong - that doesn't make it ambiguous. It's like saying if e-calcs started saying 1+1=3 then that must mean 1+1 is ambiguous. It might create confusion, but it doesn't mean the Maths is ambiguous.
Brackets are ALWAYS first.