Help with the symbols (1 Viewer)

[Dragonmaster262]

Okay I'm doing Trigonometric Equations and there a few symbols in my book that I don't get.

sinx = sina


or


What's K and J? And what's that symbol that looks like a capital E mean? If it isn't too much trouble could you guys also explain what the rule is saying?

 

[GUSSSSSSSSSSSSS]

k is a constant
J im guessing is standing for integers
and that E thing means "set of"

so in that case it means that k is part of the set of integers
which means k is an integer

wat writing the solution like that does, is make it a general solution
in that it can apply for a multitude of values
because as i'm sure you know sin60 is the same as sin420 and sin780
so to express them all in the one solution, the 2kpi (multiples of 360 degrees) is added on

you get??

 

[Drongoski]

Here k is an integer
A more concise way of expressing this is to say that " k is a member of the set J " where J is the set of integers. The e-like symbol stands for "is a member of the set "

 

[Dragonmaster262]

k is a constant
J im guessing is standing for integers
and that E thing means "set of"

so in that case it means that k is part of the set of integers
which means k is an integer

wat writing the solution like that does, is make it a general solution
in that it can apply for a multitude of values
because as i'm sure you know sin60 is the same as sin420 and sin780
so to express them all in the one solution, the 2kpi (multiples of 360 degrees) is added on

you get??

I get it now. Thanks

 

[GUSSSSSSSSSSSSS]

I get it now. Thanks

no problem



btw i got ya this time drongoski lol
look forward to future battles (in other words i look forward to u pwning me in math XDD)

 

[annabackwards]

Same thing as what everyone said but that's how i would say it: K is an interger of the real field J.

Those equations are the general trigonometric solutions aren't they?

 

[Drongoski]

no problem



btw i got ya this time drongoski lol
look forward to future battles (in other words i look forward to u pwning me in math XDD)

Most welcome kid. Did you notice I was typing in LaTeX and that slowed me down. I had to retype all over again when I realised that..

Remember what I said: "like sharks waiting to pounce". It's crazy. I'm supposed to be a tutor and here I'm doing it for free (since there are millions dying to do the same). And I get abused sometimes. How can I make a living. Ha! Ha!

 

[GUSSSSSSSSSSSSS]

Most welcome kid. Did you notice I was typing in LaTeX and that slowed me down. I had to retype all over again when I realised that..

Remember what I said: "like sharks waiting to pounce". It's crazy. I'm supposed to be a tutor and here I'm doing it for free (since there are millions dying to do the same). And I get abused sometimes. How can I make a living. Ha! Ha!

hahaha

yeh i cant handle that latex thing, FAR too complicated for me, but then again all my solutions look very messy and unclear as a result

hahaha "abused"
well i keep getting told i have to "spread some rep around" before i can give it to drongoski again lol you answer SO MANY q's, always put up the solutions before me too haha

 

[Dragonmaster262]

hahaha

yeh i cant handle that latex thing, FAR too complicated for me, but then again all my solutions look very messy and unclear as a result

hahaha "abused"
well i keep getting told i have to "spread some rep around" before i can give it to drongoski again lol you answer SO MANY q's, always put up the solutions before me too haha

What are reps?

 

[hermand]

What are reps?

that tiny little green box under your name in the post. you can give rep to people by clicking on the scale-like icon at the bottom of the light blue section [where everyone's info - eg name etc] next to their post. for every box, you need 100 rep points. you can check how many you have by going to user cp in the title bar, or by clicking on the scale icon on your own posts.

 

[jet]

Though you would think it would be a Z instead of a J, since Z is the letter which represents the set of integers.

 

[kwabon]

Though you would think it would be a Z instead of a J, since Z is the letter which represents the set of integers.

Z and J both represents the set of integers

 

[hermand]

it would make much more sense if it said k€R [that € is supposed to be the above one] unless J has parameters on it, or you're dealing with complex numbers, which you don't in prelim.

i use it in graphing aswell when they ask for range [x€R which means x is an element of the reals, ie. all real x] and domain.

 

[jet]

it would make much more sense if it said k€R [that € is supposed to be the above one] unless J has parameters on it, or you're dealing with complex numbers, which you don't in prelim.

i use it in graphing aswell when they ask for range [x€R which means x is an element of the reals, ie. all real x] and domain.

Yeah, but for this, k is an integer, as they are general solutions, as so it would be k∈Z (or apparently J now). But I know what you mean for that graphing.

 

[hermand]

Yeah, but for this, k is an integer, as they are general solutions, as so it would be k∈Z (or apparently J now). But I know what you mean for that graphing.

yeah. i think i write R as a force of habit. but Z does make the most sense, cause even though CN aren't dealt with they should still be considered in the formula. i have seen J written before from memory.

 

[jet]

I think you may be confusing Z for the complex numbers instead of the integers...?
The complex numbers are represented by C, the imaginary numbers by I.

 

[Drongoski]

yeah. i think i write R as a force of habit. but Z does make the most sense, cause even though CN aren't dealt with they should still be considered in the formula. i have seen J written before from memory.

from memory, I've seen both Z and J used to represent the set of integers. But in this context, R, the set of reals must never be used, as it would imply that k can be 7.2307 say as it is clearly not intended.

Someone earlier referred to J as a field. In maths, field has a special meaning. For 3U & 4U purposes, the most obvious fields are the sets Q of rational numbers,R of real numbers and C of complex numbers. Z, the set of integers is not a field.

I think there is a brief blurb on fields in the appendix of Cambridge 4U.

 

[jet]

I think there is a brief blurb on fields in the appendix.

Yeah, there is. In the 4u cambridge book.

 

[Drongoski]

Yeah, there is. In the 4u cambridge book.

Thanks. haha ... in my hurry I omitted to mention the Cambridge 4U book.

 

[hermand]

ah yeah that makes sense. i meant to write a question mark at the end of all that. geez my brain is bad in the holidays =||. i evenremember the little diagram explaining that. sorry for being so out of it.

EDIT; just realised why i was confused, cause z is usually the letter used for a CN and when i use sine general formulas i write where k is an integer out the long way. thanks for correcting me on that one. you can tell that English isn't my forte, letters confuse me. numbers are much better =]]. haha.