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| Exponents |
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| ebastler:
--- Quote from: metrologist on April 09, 2019, 03:13:54 pm ---I'm sure the image below will illustrate another failure of applied context. --- End quote --- At the danger of repeating myself: https://en.wikipedia.org/wiki/Order_of_operations#Unary_minus_sign --- Quote ---Some applications and programming languages, notably Microsoft Excel (and other spreadsheet applications) and the programming language bc, unary operators have a higher priority than binary operators, that is, the unary minus has higher precedence than exponentiation, so in those languages −32 will be interpreted as (−3)2 = 9. --- End quote --- |
| Wimberleytech:
http://mathforum.org/library/drmath/view/69058.html |
| RandallMcRee:
--- Quote from: metrologist on April 09, 2019, 03:13:54 pm --- --- Quote from: soldar on April 09, 2019, 08:48:35 am --- --- Quote from: metrologist on April 09, 2019, 02:14:52 am --- Yes, thanks all. I see no reasonable solution to my problem. --- End quote --- What's your problem? --- End quote --- My applied calculus exam had 10 parts to solve: a bowling ball is dropped onto a table at t0. Show the derivations of the equations to, and calculate a number of things, such as the speed of ball at impact and time; the position, velocity, and acceleration of point (x,y) on the table at time tn. You are given such things as the modulus of expansion of the table (legs considered infinitely rigid), its thickness, density, and all the other things I've forgotten that you'd need to actually solve the problem. I got all 10 parts correct and aced the course. I ranked the top fifth in my graduating class, and have both physics and applied engineering degrees. I was trying to apply context of primary school introduction to exponents. The only question I had was the one I could not answer. I looked at it, tried to apply context, and arrived at the wrong answer. I'm sure the image below will illustrate another failure of applied context. --- End quote --- Are you trolling? I ask because you put in a lot of stuff about your past performance but left out the most important piece of information that would allow someone to help you! I.e. What exactly are you confused about?? My guess is that you were never taught properly about operator precedence. It creates ambiguity in expressions like -3^4. If you are actually still confused try to explain (in words). |
| newbrain:
--- Quote from: tggzzz on April 09, 2019, 07:48:35 am ---see APL for some interesting examples :) --- End quote --- APL, my first love...though sadly mostly forgotten. :'( Its rules are is astonishingly easy: right to left evaluation of expression, and that's it. Even the tirade on WP about long right and short left function context seems a bit of mental wankery: it is simply the application of the same rule. |
| soldar:
--- Quote from: metrologist on April 09, 2019, 01:00:25 am --- What is the answer to this? -34 --- End quote --- OK, with the additional information you have provided the answer is most definitely "it depends". The order of operations is a matter of convention and, as such, there is no universal correct answer. Unless otherwise stated the most common convention is what Wikipedia says and has been said here. Then Excel states and abides by the exception: --- Quote ---There are differing conventions concerning the unary operator − (usually read "minus"). In written or printed mathematics, the expression −32 is interpreted to mean 0 − (32) = − 9,[1][3] Some applications and programming languages, notably Microsoft Excel (and other spreadsheet applications) and the programming language bc, unary operators have a higher priority than binary operators, that is, the unary minus has higher precedence than exponentiation, so in those languages −32 will be interpreted as (−3)2 = 9.[4] This does not apply to the binary minus operator −; for example while the formulas =-2^2 and =0+-2^2 return 4 in Microsoft Excel, the formula =0-2^2 returns −4. In cases where there is the possibility that the notation might be misinterpreted, a binary minus operation can be enforced by explicitly specifying a leading 0 (as in 0-2^2 instead of just -2^2), or parentheses can be used to clarify the intended meaning. --- End quote --- It is not "wrong". It is just another convention. If you do not specify people will assume the most widespread convention is in use. If you ask "what is the correct result in Excel?" that is a different question with a different answer. Note that it is easy to avoid any ambiguity by just using parentheses. This is like asking if people should drive on the right hand side of the road. The answer is yes because people are assuming you are in a country where that is the convention but if you further clarify you are talking of England then the answer changes. So, --- Quote from: metrologist on April 09, 2019, 01:00:25 am --- What is the answer to this? -34 --- End quote --- My answer is "where?". |
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