Search results

On the most left, f(x) appears to be increasing, that is, f'(x) >0. The concavity of f (x) is also negative, so f''(x) <0. That means for the f'(x) curve, the derivative (ie. The gradient) of that curve is also negative since f"(x)<0. So we can say that the f '(x) starts positive (above the x...

Where did you get this question from?

Thanks. My teacher said we should memorise them but I have yet to see a HSC question asking for it specifically.

Do we need to memorise both diagrams?

Not that i can remember but i will post if i do

Hahah, i hope you didn't do the ethanol one on purpose

Dude what did your teachers say..? Also do you laugh whenever a chem exam asks for safety precautions for an experiment? Lol

Curious for the solution. I tried it but I realised can't the man just change directions during his path?

imgur.com/a/vbwwR Check q20 tho. not sure

Re: HSC 2015 2U Marathon let y = f(x) be an even function So, y = f(x) = f(-x) Differentiating wrt. x, dy/dx = f'(x) = f'(-x) * d(-x)/dx f'(x) = -f'(-x) which is odd

Re: HSC 2015 4U Marathon $ Consider, $ \cos \frac{A-B}{2} - \sin \frac{C}{2} = \cos \frac{A-B}{2} - \sin \frac{180 - A - B}{2} ( $ since $ A+B+C = 180 ($ angle sum of a triangle $ ) ) = \cos \frac{A-B}{2} - \sin(90 - \frac{A+B}{2}) = \cos \frac{A-B}{2} - \cos \frac{A+B}{2} = 2...

Re: HSC 2015 3U Marathon y = x + \sqrt{y + \sqrt{x + \sqrt{y + \sqrt{x + ... } } } $ Find $ \frac{dy}{dx} $ in terms of y and x $

Re: HSC 2015 2U Marathon ln(x) - 3 / ln(x) = 2 (ln(x))^2 - 2ln(x) - 3 = 0 (lnx - 3)(lnx + 1) = 0 lnx = 3 , lnx = -1 x = e^3 , e^-1

Re: HSC 2015 4U Marathon \int_2^{k+1} \ln(x) dx > $ part b $ $ will give you the answer $ ($ as it is above the y = ln(x-1) curve $) mr mai

Isn't that how MC is normally answered?

Re: HSC 2015 4U Marathon No since everyone has a different answer we can deduce that the remaining 9 people must match up to 0,1,..., 8 handshakes each

Re: HSC 2015 4U Marathon Don't think this would fall under any topic in 4U but I found a nice math/logic puzzle $ Five couples go to a party and start shaking hands. You don't shake your spouse's hand or (of course) your own. One of the men, Jake, surveys everyone and asks how many they...

re: HSC Chemistry Marathon Archive You only have to put the products as water and one other pollutant molecule. I find it easy to just put the products as H2O and CO

Re: MX2 2015 Integration Marathon Is there a case when it's not? o.O

Re: MX2 2015 Integration Marathon Is there a formal proof for that?? If 'c' is a constant independent of x, then you can just bring it out of the integral edit: https://en.wikipedia.org/wiki/Constant_factor_rule_in_integration