[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

View post   
File: 62 KB, 633x758, 28fj3w.jpg [View same] [iqdb] [saucenao] [google]
10427747 No.10427747 [Reply] [Original]

I can't take this anymore. I work hard and practice but I can't do calculations fast enough on tests and I constantly make arithmetic errors. Aboit 60% of the time I calculate the inverse of a matrix via elimination I get one or more values wrong. Tests are only 50 minutes with no calculators. I want to kill myself. I can't take it anymore. I work and I work but you need to be fucking perfect to do well in this subject.

>> No.10427780

Got gud OP

>> No.10427788

>>10427747
calculate the inverse as A^(-1) = adj(A) / det(A)

>> No.10427809

Just stop making errors of arithmetic? You're not eight.

>> No.10427814

lmao what kind of an arithmetic error can you even make in a lina question? Just use your imagination to visualise linear transformations you fucking brainlet

>> No.10427826

>>10427747
just read Halmos bruh

>> No.10427856

>>10427809
Maybe I can't when I'm under pressure because there's less than an hour to write the test? I really don't like throwing around words like "fair" and "unfair" but I think this case warrants it. I don't believe it's fair to test someone on how fast they can do calculations like this. I could tell you how to solve any problem on these tests but maybe I just can't complete the steps in the allotted amount of time. In most applications, a computer is going to be computing matrices and I can't imagine a non-arbitrary reason to test someone on the ability to solve a matrix fast. Also, even writing down each step takes time. When there are many steps and you need to rewrite a matrix many times, it gets overwhelming. I know I sound bitter, and I am, but this class seems contrived to me. The content or operations are not difficult to grasp but that doesn't matter because if you can't perform calculations faster than a computer and write fast, you won't succeed to matter what you do.

>> No.10427876

>>10427856

Fifty minutes is a long time. How many questions are you expected to solve?

>> No.10427881

>>10427876
Most tests are 5-6 questions.

>> No.10427928

Don't give up. You're smarter than you think.

>> No.10427936

>>10427856
Sounds like you're not a good test taker. Make sure that, within 48 hours of your test, you've already done all the studying you need to do. This takes a lot of work and you seem to be up for something like that. Take those 48 hours and relax, don't psyche yourself out by over studying. If you're working hard all semester then those last 48 hours of cramming will only stress you out.

>> No.10428231
File: 25 KB, 683x600, Matrix_multiplication_diagram_2.svg.png [View same] [iqdb] [saucenao] [google]
10428231

>>10427747
Same shit here. Things like 2-(-2)+2 and I'm wrong 50% of the time. I've just developed a couple of tricks that let me make fewer mistakes (don't know if it is just my brain works better when I do things this way): when multiplying two matrixes write them not one after another but above each other, like in picrelated, which is more visual than regular way. When finding determinant of the matrix always use the rule of sarrus because it is more dumb compared to rref. And in general I tend to choose approaches that are as dumb and as visual as possible: if you can throw out absolutely all thinking steps and boil everything down to simple algorithm you are less likely to make mistakes. (Like tabular integration vs integration but parts, technically identical, but first one is 100 times faster and easier).

And I also always write matrices in square braces, don't know but it makes it easier for me.

And you might also want to develop habit of how you arrange steps of your solution for particular types of problems and follow then carefully each time.

>> No.10428238

>>10427856
I don't understand why you make mistakes. Just fucking get it right the first time. If you can't build up rigor for something as simple as this, why should you get a degree anyway?

>> No.10428993

A few careless errors are expected, but if you're screwing up 60% of the time, something's horribly wrong.
Are you showing up hungover, or after having stayed up for two days straight?