Should I memorize the source of formulas or just understand it?

[Mustave Ashab Behon]

I always try to understand the source of a formula but later i cant remember it well, most of the time i completely forgets it. Should i memorize the sources of formulas also or just understand it? Is it necessary to make myself remember the sources always? I saw my friends can remember all the sources of formulas perfectly.

 

[Vanadium 50]

What do you think the answer is?

 

[Mustave Ashab Behon]

What do you think the answer is?

I think i shouldn’t, but im getting confused

 

[Vanadium 50]

Shouldn't do what? Please write clearly, or we won't be able tp figure out what you are saying, much less help you.

 

[Mustave Ashab Behon]

Shouldn't do what? Please write clearly, or we won't be able tp figure out what you are saying, much less help you.

I think i shouldn’t memorize the sources of formulas, rather understand it and memorize the main formula

 

[PeroK]

I always try to understand the source of a formula but later i cant remember it well, most of the time i completely forgets it. Should i memorize the sources of formulas also or just understand it? Is it necessary to make myself remember the sources always? I saw my friends can remember all the sources of formulas perfectly.

You can't function if you can't remember anything. The more you study, the more information you should retain. A lot of building up a solid memory of a subject should come naturally from familiarity with the material.

How much time you should spend explicitly memorising formulas depends on the context. For example, it may be sufficient to remember that there is a simple formula relating $\sec^2 \theta$ and $\tan^2 \theta$. You can always look it up. But, if you forget that the two are related, then that may be more of a problem. Likewise, it may be sufficient to recognise that something is a standard integral - even if you then have to look it up. Or, remember the cases where trig substitutions tend to work.

As I've got older, I've found it more difficult to remember precise formulas. I still tend to remember that there is something. But, more and more, I have to look things up to get the precise formula. Like acceleration in polar coordinates. When I was a student 40 years ago, I would remember something like that without trying. Not any more.

You need to find a way of working that is successful given the amount of material that you can memorise precisely.

 

[Mark44]

For example, it may be sufficient to remember that there is a simple formula relating $\sec^2⁡θ$ and $\tan^2⁡θ$. You can always look it up. But, if you forget that the two are related, then that may be more of a problem.

The formula that @PeroK refers to above is $\sec^2\theta = \tan^2\theta + 1$, and there is a similar one that relates csc (cosecant) and cot (cotangent).

Both of these are derived from the identity $\sin^2\theta + \cos^2\theta = 1$. By dividing both sides of this equation by, respectively, $\cos^2\theta$ and $\sin^2\theta$ you can get the tangent and secant identity or the cotangent and cosecant identity. My point is that it's possible to start from a basic identity or formula and derive others from it, making it unnecessary to memorize each and every identity or formula.

 

[symbolipoint]

I think i shouldn’t memorize the sources of formulas, rather understand it and memorize the main formula

Then, there you go. Very good to do that!

 

[symbolipoint]

I always try to understand the source of a formula but later i cant remember it well, most of the time i completely forgets it. Should i memorize the sources of formulas also or just understand it? Is it necessary to make myself remember the sources always? I saw my friends can remember all the sources of formulas perfectly.

Most important are skills and understanding.
Next of importance if it is what you want, is to understand how the formulas were developed.

A person who is interested in academic success and ability to find employment should focus on understanding and skills.

 

[Choppy]

Sometimes on the path to understanding you need to start with memorization. In order to work with a formula, you need to remember what it is (or at least enough about it to know where to look it up).

After that you need to work with it, apply it to lots of problems, and make sure you get feedback so that you know when you're applying it correctly. Sometimes students develop a superficial understanding of a concept and then move on and end up struggling with it during examinations. In such situations, often, they understood a basic conceptualization, but didn't develop much skill in terms of the application. You want to get to a point where, when presented with a new problem that you haven't encountered before, you'll have enough experience to draw on that you'll be able to apply the concept or equation correctly. That's the deep understanding that you'll want to have.

 

[gmax137]

I always try to understand the source of a formula but later i cant remember it well, most of the time i completely forgets it

I'm curious what you mean by "source." Do you mean the name of the book where you read the formula? Or do you mean the derivation of the formula? The book is not important, the derivation is important.

 

[symbolipoint]

I'm curious what you mean by "source." Do you mean the name of the book where you read the formula? Or do you mean the derivation of the formula? The book is not important, the derivation is important.

A good bet is he means the originating source; the person or group which either discovered a relationship among quantities or who derived a formula at a time before other personnel made the derivation. He may too mean, from what book or what journal article; but these are for him to make clear for us.