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Comment by WalterBright | Hacker News Reader

If a reference is needed to do simple arithmetic, algebra, and trig, then you never learned it in the first place.

At least when I was in college, there was an approved formula book that was allowed in exams.

Need the formula for the moment of inertia of a shell sphere? The coefficient of linear expansion of gallium? Fourier series of a sawtooth wave? If you've somehow forgotten the formula for the mean of a sample? It's all in there.

There were of course some things that weren't in the formula book - and if you had to look up every last thing, you'd face a lot more time pressure in exams.

Caltech exams were open book / open note. The books didn't help much :-/ as the exams were not about regurgitating knowledge. I never bothered to memorize anything at Caltech, yet I wound up with an encyclopedic knowledge of things like trig identities. Sort of like I wound up knowing most of the x86 opcode encodings, although since I later abstracted that, it has slipped my mind a bit.

Prefixes come first, 1 byte each, order doesn't matter except that REX, if present, must come last. Then the opcode, 1-3 bytes. Followed by Mod R/M byte, if present. Followed by SIB byte, if present. Followed by address/immediate, 1, 2, 4, or 8 bytes, if present.

Ugh; there's a reason why I'm switching my architecture course to MIPS32.

One day I realized I could just look at a hex dump and see some (not all) of the instructions in my head.

People regularly memorize knowledge that they need to apply, and an intelligent person can learn what they need to know as they need to know it.

How many people will ever have a need to know the derivatives of the inverse trigonometric functions?

Scientists and engineers will need to. Just like if you're a C programmer and have to look up what a for-loop is - eh, you haven't learned much of any C.

>Scientists and engineers will need to.

No, they wont.

Yeah, I worked with some that weren't able to do that. They were better off leaving the math part to others.

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