.

[andrewloppol]

.

[TrueTears]

1. Correct.

2. What do you mean what it "says", it "says" what it means. Ie, for all x, x is larger than 3

3. , the first R is the domain of the function, the 2nd R is the codomain (the range exists as a subset of this codomain)

[TrueTears]

The distance of any point to the y axis is just the x ordinate.

Thus

Thus



Rest should be ok.

[m@tty]

...

...

Typo?

Should it not be

[TrueTears]

typo indeed, as my 2 magically turned into a 3

[m@tty]

Yes
Was that a typo as well?

[m@tty]

Fail

Yes you are right

[TrueTears]

Someone is stealing the x's and 2's tonight.

[Ilovemathsmeth]

Hey guys, my year 11 methods teacher just doesn't understand my questions..

Question 1:
Is this okay:

when differentiated:

Or is that incorrect notation? I know you can write and but what about just ?

Question 2:
What exactly does this say:
{} (I know what it means, but what does it say)

Question 3:
What exactly does this say:


Just a problem I'll have no time to ask my teacher before the SAC:
Find the equation of the curve which passes through the point (-1,2) and has the property that for each point on the curve, the gradient equals the square of the distance between the point and the -axis.


Thanks in advance

1. Correct, but very rare notation. You're better off using dy/dx. If y = kx etc is the notation, use dy/dx preferably although I wouldn't call y' wrong. However, never use f'(x) when given a y notation as the examiners are fussy that way, you have changed the relationship into a functional one. So if it is called f(x) = kx etc use f'(x). Likewise, dy/dx apparently is incorrect notation to use when using functional notation. Confusing...

2. That says, x is such that x is greater than 3.

3. That says, f is a function such that it has a domain that extends over all real numbers in the cartesian plane which has a co-domain of R, i.e., the range is expected to be a subset of R but not necessarily is R.

[TrueTears]

Hey guys, my year 11 methods teacher just doesn't understand my questions..

Question 1:
Is this okay:

when differentiated:

Or is that incorrect notation? I know you can write and but what about just ?

Question 2:
What exactly does this say:
{} (I know what it means, but what does it say)

Question 3:
What exactly does this say:


Just a problem I'll have no time to ask my teacher before the SAC:
Find the equation of the curve which passes through the point (-1,2) and has the property that for each point on the curve, the gradient equals the square of the distance between the point and the -axis.


Thanks in advance

1. Correct, but very rare notation. You're better off using dy/dx. If y = kx etc is the notation, use dy/dx preferably although I wouldn't call y' wrong. However, never use f'(x) when given a y notation as the examiners are fussy that way, you have changed the relationship into a functional one. So if it is called f(x) = kx etc use f'(x). Likewise, dy/dx apparently is incorrect notation to use when using functional notation. Confusing...

2. That says, x is such that x is greater than 3.

3. That says, f is a function such that it has a domain that extends over all real numbers in the cartesian plane which has a co-domain of R, i.e., the range is expected to be a subset of R but not necessarily is R.

1. y prime notation is often used in DE's, it is just as common as f(x)
2. Shouldn't it be for ALL x? just x could mean any subset of ALL x.

[Ilovemathsmeth]

:S well i only saw it like once or twice out of the many practice exams i did...it's not unheard of, just not as popular as dy/dx. then again im not sure what D.Es are exactly. what does it stand for?

2. its implied that when you say x is such that x is greater than 3, it is for all x because thats simply the way it is expressed in the domain. i dont reckon you'd need to specify it further because you've already said x is greater than 3, i.e., the domain is (3, infinity) but if it makes it more succinct go ahead.

[hyperblade01]

D.E. = Differential Equations

Equations that have derivatives in them

[TrueTears]

D.E. = Differential Equations

Equations that have derivatives in them

Yeap, you don't want to be writing in Leibniz notation all the time so y' and y'' are very common.

[Mao]

D.E. = Differential Equations

Equations that have derivatives in them

Yeap, you don't want to be writing in Leibniz notation all the time so y' and y'' are very common.

Actually, Leibniz notation are quite popular in DEs, especially since many methods require manipulation of infinitesimals.

[Ilovemathsmeth]

well i dont do specialist maths lol

so i didnt know that. there were only two diff equations in methods which were kinda disguised. are diff equations difficult? everyone tells me its the hardest part of spesh...