pouët.net

How do you spell y'(t) and ± ?

1) derivative of y (probably to t)
2) plus or minus (i hope)

spelling is naming the letters that form a word btw

why prime of tea

1) ok
2) Minus-plus_sign - wikipedia
3) questiomnark

you meant "pronounce"

1) derivative of 'y' with respect to 't'

soo... how do you say them in Portuguese?

Open a 'Math/Portuguese related question (no it's not a counter-topic)' topic for that.

eles.

y'(t) --- I agree with imbusy. That's exactly how I say it.

± --- plus or minus

you don't spell it, that's the beauty of math symbols universality.

it not suposed to be a derivative... it's like a... similar function, yeah bad notation :P

anes (almost) got it right: "y prime t"
the other one is "plus-minus" i think (minus-plus is the other sign)

xernobyl':
Oh, in that case, I'd say "y prime at t".
For reference, "f(x)" would be "f at x".. and "f'(x)" would be "f prime at x".

I'd say "f of x"

This might help: http://www.math.helsinki.fi/engl.pdf :)

Laxxy Graxxygaxx:
Saying it that way, it only makes sense when talking about the function when it's not actually being applied. For instance, consider the following-
f(1)
That's "f at 1". "f of 1" doesn't make a lot of sense. Considering f(x) to be "f at x" can make sense in all cases and it forces some interesting understanding of variables and constants.

1) y tag
2) plus minus (variable)

math.helsinki.fi
point, I guess :)

let me add to the "at vs. of" discussion that people actually using this stuff (as opposed to commenting on it here) simply say "f x"... :)

2) I heard a Britton saying it: "give or take"

in danish it would be:

f(x) = f af x
f'(x) = f mærke af x

translate that to english:

f af x = f of x
f mærke af x = f prime of x

.. and that does indeed cover the case where you're not applying the function to x :-)

"f von x" in german, but as always in german you can say it in a long way also (and only then it's 100% correct):
"f an der stelle x"

sorry the correct one has to be:
"der funktionswert von f, an der stelle x"