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    CHEM1011 or MATS1101?

    Hey guys, I'm wondering which of those subjects to do for my second semester. I'm a first year doing Civil Engineering/Commerce. I was considering doing CHEM1011 since I've heard it's easier than MATS1101, but MATS1101 is the recommended elective so I'm not sure if I should. Also, instead of...
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    Hurlstone Agricultural High School to relocate to Hawkesbury in 2020

    http://www.dailytelegraph.com.au/newslocal/macarthur/hurlstone-agriculture-high-school-to-relocated-to-hawkesbury-in-2020/story-fngr8h70-1227613681204?nk=397c885e7bd4ed622c08b1f4bb127d82-1447815725...
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    Options

    Not sure if they've been uploaded yet: http://imgur.com/a/ByfFx
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    Exam Paper

    http://imgur.com/a/tA61F Question 11: http://imgur.com/ntz14kz
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    Trig question

    Hey can someone do this question for me: $Find the general solution(s) of $\sin{x}+\cos{x}=\cos{2x}$.
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    Polynomial questions

    $The polynomial $x^3-3x+2=0$ has roots $\alpha, \beta, \gamma$. Find $\alpha^4+\beta^4+\gamma^4$. What's the easiest way to do this? Also, how do you do those questions where you are asked to find a polynomial with roots $\alpha^2, \beta^2, \gamma^2, given that another polynomial (e.g...
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    Induction Question

    $Prove for $n\in \mathbb{N}$, that $\sqrt{n} \leq \sum_{r=1}^{n}\frac{1}{\sqrt{r}} \leq 2\sqrt{n}-1$. Not sure how to do this. Tried splitting the inequality up into \sqrt{n} \leq \sum_{r=1}^{n}\frac{1}{\sqrt{r}} and \sum_{r=1}^{n}\frac{1}{\sqrt{r}} \leq 2\sqrt{n}-1 and then prove these...
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    Determining polarity of an AC generators terminals

    Can someone explain how you do this? Here is an example question:
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    ATAR Estimate

    School rank: 24 English Advanced: 92/131 Biology: 27/75 Chemistry: 36/106 Physics: 28/74 2U Maths: 3/104 3U Maths: 46/120
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    Binomial theorem question

    $5(i) In the expansion of $(2x+5)^{20}$ in ascending powers of $x$ show that there are two successive terms with the same coefficient, which is the greatest of any of the coefficients. Express this coefficient in index form.$ \\ \\$I've found the coefficient to be $\binom{20}{15}2^55^{15}$. and...
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    2U Trials 2015

    braintic's posts in the 3U and 4U sections reminded me that I had these: https://drive.google.com/open?id=0B_8TuhB8fbqDaUFGcXNCSDVnaDg
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    Rate of Change Q

    $Sand is pouring from a chute at the rate of 12 m^3$/$min. The falling sand forms a conical pile on the ground, whose altitude is always equal to the diameter of the base. Show that when the altitude is $h$ m, the volume $V$ m$^3$ of sand in the pile is given by $V=\frac{\pi h^3}{12}$. I...
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    Applications of Calculus Question

    $A moving particle has an acceleration $a$ metres per second per second at time $t$ seconds $(t\geq0)$. The acceleration of the particle is given by $a=2\pi^2\cos{(\pi t)}$. At time $t=0$, the object is at the point $x=0$ and has a velocity $v=\pi$ metres per second. \\(c) Show that the...
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    Logarithms question

    $If $2^x=5^y=10^z$, using logarithms to base 10, or otherwise, show that $\frac{1}{z}=\frac{1}{x}+\frac{1}{y}$.
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    Induction Questions

    Was looking through the 3U marathon and saw this question. Can someone help?
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    Perms/Combs

    If you had a group of 20 unique objects, and were asked to choose 5 of those objects (where order does not matter), would the number of ways of doing this be 20C5=15504 or 20x19x18x17x16=1860480? I've been told it is the first option, but I don't see why the second option is wrong. Choosing 1...
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    Parabola Question

    Saw this question in an exam paper but unfortunately there were no answers. Could someone please assist? In the Michaelson and Morley experiment the pair was attempting to prove the existence of the luminiferous aether by setting up the equipment as show below. Mistakenly, they used a...
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    Calculating photons per second

    I was looking at the in2Physics@HSC textbook and saw this example question. Can someone please explain how they get the formula for number of photons per second for b.?
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    Inverse Trig Integration Question

    Hey how would you do this question without using substitution? \int \frac{1}{\sqrt{a^2-(x-b)^2}} \,dx
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    Inverse Trig Question

    Hey could someone please help with the following? \textup{For the domain }-1\leq x\leq1\textup{, show that }\cos(\sin^{-1}(x))=\sqrt{1-x^2}, and also: For 14i., what exactly is the question asking me to do?
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