Search results

yea.. what is it? I thought I could use (A+B)^3 = A^3 + 3A^2B + 3AB^2 + B^3 but doesnt look like I can if u mean something like x= [-b +- sqrt(b^2 - 4ac)] / 2a I must say the cubic one is really ugly

grr im alergic to that formula thanks ngai

f(x): y = 3x - x^3 inverse f(x): x = 3y - y^3 can we make y the subject in inverse f(x) Thanks. EDIT: I was told this Q by someone, and it turns out this someone lied to me.. u dont need to be able to do this Q :p

no the reason it has 302 digit is because 10^301 has 302 digits.. 10^301.99999999999 has 302 digits.. and 10^302 has 303 digits, like what withoutaface mentioned (although now.. he keeps changing faces.. hmm....)

why exactly r u doing 2U paper? btw how do u guys find 2003 HSC?

oh, that explains, haha so wad have u been doing in yr11 though? do many schools postpone calculus until yr 12?

and I think this only happens recently (before it always showed Last edited on...)

lim (δ-->0) ?? looks interesting, hehe... no I don't think you can have lim delta->0 because delta is not a quantity. need to be delta(x) or delta(something). (d/dx * y) * y = dy/dx * y d/dx * (y^2) = 2y * dy/dx But never use the * because it's not a product as I understand it. It...

Before I start, I need to say that 2U students should really ignore this junk and ignore this thread except the first few posts. the last line is wrong. you should have have y' = a*y, that's it and the second last line is not necessary. If you wanna differentiate the second last line for...

or you can make a virtual burn burn into an image file ^_^ but anyway the program mentioned by equiski is free so u wont need to make virtual cd.

Yet another way to look at implicit diff: you just differentiate both sides independently with respect to x. (or to y if that's what you need) dy/dx is indeed a fraction... some ppl might disagree but it can be treated as fraction. Oh also, thats the correct proof. you're not using the...

I wonder why the boys must be separated by the girls.. ;) In invisible text: just one of my pointless posts :P

2004 Independent AOS 2004 Independent Paper 2 Note: if they're not Independent papers pls tell me.. I'm quite sure they are

I have it but be4 I scan I need to know if u stll need it and if nobody else has it already...

it's Rench's example. I just used it to show how we can use discriminant and the logic behind it. but it happens that the discriminant in that example is in fact not negative. when I said: I tried to point out the fact that a positive leading term of a quadratic in x doesn't necessarily...

at first I thought yes. but, what about: writing x^2 - (y^2+y)*x as a quadratic in y? you get -x as the leading term, which can be negative and positive this is confusing :confused:

hmm.. why? I just realised.. for Rench's Q the discriminant is positive... and by inspection, or alternatively by putting x=1 and y=2, the statement x(x-y^2) > xy doesn't hold.

actually i've never used the discriminant technique :D might be useful in 4U... hope so. anyway, taking discriminant for x(x-y2) > xy is a bit of a subtle point.. I'll try to explain it in case anyone didnt know already let us review what we usually do with discriminant. suppose y = ax^2...

>> Are there many other ways in which an inequality could arise? << We can make infinetely many inequalities. >> Do these generally require the use of the discriminant to prove? << Not really. One of the common methods is to complete the square and show LHS - RHS > 0 or something along...

some ppl dont wanna memorise that formula