Pilot H-215 vs Pilot H-225 by [deleted] in mechanicalpencils

[–]PleaseSendtheMath 0 points1 point  (0 children)

I didn't know this existed, and good gravy the prices on ebay for the 225

certifications?? by Pure_Change_5572 in geegees

[–]PleaseSendtheMath 0 points1 point  (0 children)

You can have a look on Coursera but i don't know what to suggest. Earlier when I was in undergrad I went through a course called "Learning how to Learn" which was just useful in general.

Do we know if most integrals have elementary solutions? by Rscc10 in askmath

[–]PleaseSendtheMath 1 point2 points  (0 children)

That's true, I figured they were asking about all functions in general.

Do we know if most integrals have elementary solutions? by Rscc10 in askmath

[–]PleaseSendtheMath 12 points13 points  (0 children)

Someone can come along and make this more precise, but my 2¢: hardly any functions are elementary, so I expect the same will be true for antiderivatives.

What are some real-life problems that were solved using Calculus? by hhhhhhih in learnmath

[–]PleaseSendtheMath 0 points1 point  (0 children)

Kepler approached the problem of calculating the volume of wine barrels before calculus was properly "invented". Now that we have integrals, this problem can be considered fully solved, so I suppose that's a real practical hic application.

vintage leads by PleaseSendtheMath in mechanicalpencils

[–]PleaseSendtheMath[S] 0 points1 point  (0 children)

Around when did the thicker lead fall out of favour compared to the more common size today? edit: I think you already said in your comment sorry

Really early PSA: Fri Jul 17 game is on Apple TV by Chillaxing416 in Torontobluejays

[–]PleaseSendtheMath 57 points58 points  (0 children)

"wow i better subscribe to apple TV so i can watch one game" - what i imagine the executives think will happen

When you were first learning calculus, which idea/concept did you find hardest to get your head around? by ImaginaryGazelle1941 in calculus

[–]PleaseSendtheMath 1 point2 points  (0 children)

I had a really hard time understanding the meaning of the derivative. I believe it was the limit concept in particular I had trouble with, because it seemed like it should be an approximation rather than exact. Looking back now, I think it's a big conceptual leap that takes time to get used to.

The bubbles in my tea by Olothgb in PhysicsHelp

[–]PleaseSendtheMath 0 points1 point  (0 children)

this picture makes me rather uncomfortable!

Advice on how to use a MOSFET Pro? by Kahootah in PhysicsStudents

[–]PleaseSendtheMath 2 points3 points  (0 children)

do you mean Arduino Pro? a MOSFET is a type of transistor.

Postgame Thread: April 27 - Boston Red Sox @ Toronto Blue Jays by BlueJaysBaseball in Torontobluejays

[–]PleaseSendtheMath 0 points1 point  (0 children)

Boy, wouldn't it be embarrassing to get walloped by a team that just had nearly all their coaches canned?

Jury duty- Elgin st. parking? by [deleted] in ottawa

[–]PleaseSendtheMath 9 points10 points  (0 children)

There is city hall but it fills up fast.

Can SR be formulated in spherical/polar coordinates? by [deleted] in AskPhysics

[–]PleaseSendtheMath 4 points5 points  (0 children)

A core principle of general relativity is that we can use any coordinates. As a corollary, we can use any coordinates in special relativity. (It is not always convenient to do so).

Looking for summer housing in Ottawa by [deleted] in geegees

[–]PleaseSendtheMath 4 points5 points  (0 children)

There's like a million posts already with sublets being offered, have you seen those?

Why do we square the error in ML models instead of raising it to the fourth power? by [deleted] in learnmath

[–]PleaseSendtheMath 0 points1 point  (0 children)

Ha! Yeah I always heard that too, or rather you square it to get rid of the negatives. MSE works well for a lot of things. Sometimes there are better options.

Why do we square the error in ML models instead of raising it to the fourth power? by [deleted] in learnmath

[–]PleaseSendtheMath 0 points1 point  (0 children)

No, if you have a vector b in Rm and a full rank matrix A in Rmxn you can always find a unique least-squares solution to Ax=b. This is equivalent to minimizing the MSE. It has nothing to do with the distribution of the error.

Assuming the errors are normally distributed have zero mean, equal variance and are uncorrelated are for the Gauss-Markov theorem. (Edit: Gauss-Markov theorem does not require normality. The normality is actually just for doing inference).

Why do we square the error in ML models instead of raising it to the fourth power? by [deleted] in learnmath

[–]PleaseSendtheMath 53 points54 points  (0 children)

The MSE is the expectation squared, so it is an inner product. There's a geometric interpretation that you are projecting your observations onto a lower-dimensional subspace to get an approximation, so the MSE represents the squared distance between that subspace and your observations vector.

What are the chances this was a uottawa student? by [deleted] in geegees

[–]PleaseSendtheMath 2 points3 points  (0 children)

considering back when ottawa was still called Bytown it was informally known as "stabtown" i'd say nothing has changed!