I think you’re overthinking it. The first thing you’re told when you learn algebra is that a letter represents a number and you can say “let a equal (number), b equal (number)…” so you can let pi equal whatever you want for the purposes of one simple problem.
Well, if we want to be pedantic, they never said that h is the height and r is the radius of the base circle. They could be just random numbers.
Also, since we never calculate with all the digits of pi, it is not any less weird to round to the nearest 5 and say that it’s 5, than to the nearest 0.01 and saying it’s 3.14. It just has a higher amount of rounding error.
Except pi isn’t a variable. It is a known value that we refer to as pi for convenience, and pi is a fundamental aspect of how a circle is. Saying “let pi equal 5” is all fine and well but is physically impossible, you will not be determining the volume of a cylinder if you let pi equal 5, because the ratio of a circle does not equal 5, it equals 3.14
But I suppose part of solving a maths problem is staying within the confines of the question and listening to instructions, so if someone says “using pi equals 5”, I’d just use pi equals five and take my point with grace.
I think it’s actually a very interesting question. Pi does not equal 5 in our universe, but perhaps we can think of a meaningful universe where it does? Perhaps some mathematicians/physicists can chime in?
With π=5 maths break down completely. If π=5, then e^(5i) = -1, meaning -1 = cos(5) + i * sin(5), or -1 ≈ 0.284 - 0.959 i
Intel®️ inside
Wow, that takes me back - you’re referring to the floating point bug from …98?
It’s posts like these that makes me think we’re all old here on Lemmy and then I get a response from someone who tells me they’re 18…
665.999999657838 the floating point number of the beast
Yup. Pentium FDIV bug.
I think you’re overthinking it. The first thing you’re told when you learn algebra is that a letter represents a number and you can say “let a equal (number), b equal (number)…” so you can let pi equal whatever you want for the purposes of one simple problem.
But the question is saying to find the volume of a cylinder. Which its clearly wrong.
Well, if we want to be pedantic, they never said that h is the height and r is the radius of the base circle. They could be just random numbers.
Also, since we never calculate with all the digits of pi, it is not any less weird to round to the nearest 5 and say that it’s 5, than to the nearest 0.01 and saying it’s 3.14. It just has a higher amount of rounding error.
Why are we upset by rounding to the nearest 5 for elementary schoolers when we round to 10 m/s/s for gravity in collegiate physics classes anyway?
It’s not even a bad thing to do for quick mental calculations, if you know that you will overshoot. Multiplying by 5 is easy.
You’re talking about variables. But, pi isn’t a variable, it is a constant number. This would be more akin to saying “let 7 = 9”.
Well I suppose for example rounding to the nearest integer is a method of implying “let 1.8 = 2”, no? Not too outlandish, I don’t think.
Or as I like to call pi…the little symbol thingy. But exactly yes, you get it.
Except pi isn’t a variable. It is a known value that we refer to as pi for convenience, and pi is a fundamental aspect of how a circle is. Saying “let pi equal 5” is all fine and well but is physically impossible, you will not be determining the volume of a cylinder if you let pi equal 5, because the ratio of a circle does not equal 5, it equals 3.14
But I suppose part of solving a maths problem is staying within the confines of the question and listening to instructions, so if someone says “using pi equals 5”, I’d just use pi equals five and take my point with grace.
Okay but they didn’t say 3.14 they made a little symbol thingy
I think it’s actually a very interesting question. Pi does not equal 5 in our universe, but perhaps we can think of a meaningful universe where it does? Perhaps some mathematicians/physicists can chime in?
It would be theoretically possible in a universe based upon non-Euclidean geometry.
Maybe e is 5, too?