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  1. fan96

    Amount of Work/study

    ~3 hours/day and my desired uni course is 93.00 so anything above that is fine.
  2. fan96

    ✨✨How much study?✨✨

    At home: 0-2 hours per day but before exam periods typically 3-6 hours. Most of my "study" is memorising.
  3. fan96

    4U Polynomial question HELP !!

    Notice that the required answer includes the constant term c . That should be a hint - if we were to differentiate the polynomial, we would lose c , so not only would we have to expand the cube of a binomial (which can be really messy), we would also have to rewrite the result to include c...
  4. fan96

    Probability

    Would it be valid to say that since there were r heads in n tosses, each toss has on average an r/n chance to be heads?
  5. fan96

    2014 maths 2U paper

    I remember learning this in Year 10, though not in the HSC course. But if you start from the observation that the perpendicular heights of the two similar triangles are in the same ratio as the sides then you could finish the question from there by using the area formula.
  6. fan96

    Conics help

    Is it actually true that Q must always be inside at least one of the ellipses? Suppose P lies on either of the co-ordinate axes. Then the chords of contact from P to both ellipses would be parallel (since the ellipses are 90 degree rotations of each other) and there would be no...
  7. fan96

    Study time?

    ~70% and yes
  8. fan96

    2018 HSC Marathon 3U Q and A

    i) Hint: the expression you need to prove can be rearranged to \cot \theta = \frac{1 + \tan n\theta\, \tan (n+1)\theta}{\tan(n+1)\theta - \tan n\theta} ii) Starting from the inductive hypothesis: \sum_{n= 1}^k \tan \theta\tan (n+1)\theta = -(k+1) + \cot \theta \tan (k+1)\theta...
  9. fan96

    what career should i do based on my subjects?

    Year 11 is still pretty early on, so you have a lot of time (many years) to decide. People will change their interests during high school, the HSC and even while at uni. For example, it might seem unlikely now, but later on you might develop a passion for math, science or art. Don't worry...
  10. fan96

    2018 HSC Marathon 3U Q and A

    The horizontal range of the ball is maximised when \alpha = \pi / 4. This can be easily shown by examining the equation in ii). Case 1: The ceiling allows for an angle of projection of \pi / 4. If the ceiling allows for at least this angle of projection, then \alpha = \pi / 4 is the optimal...
  11. fan96

    ATAR estimate

    School rank: 5 English Adv. (74 B6 in 2016) 178/208 Maths Ext. 2 (68 E4 in 2016) 19/119 Maths Ext. 1 (109 E4 in 2016) 47/165 Chemistry (47 B6 in 2016) 68/110 Software Design (6 B6 in 2016) 3/9
  12. fan96

    Polynomials

    Well since there are still solutions that exist then there should be at least one complex number that works.
  13. fan96

    Polynomials

    Also, I noticed that when you find the third (real) root using sum of roots and then sub these three roots into the product of roots, you seem to get an equation with certain solutions for k that contradict the question.
  14. fan96

    2018 HSC Marathon 3U Q and A

    \cos \theta =\frac{1}{2\sqrt 2} \cos \alpha + \frac{1}{\sqrt 2}\sin \alpha Applying the auxiliary angle transformation: \begin{aligned} \cos \theta &= \sqrt{\left( \frac{1}{\sqrt 2}\right)^2 + \left( \frac{1}{2\sqrt 2} \right)^2} \cos \left(\alpha - \tan ^{-1} \frac {\left( \frac{1}{\sqrt2}...
  15. fan96

    2018 HSC Marathon 3U Q and A

    Consider \triangle ATP . \sin \alpha = \frac{h}{TP} \sin \frac{\pi}{4} = \frac{h}{AT}= \frac{1}{\sqrt2} By the cosine rule, AP^2 = 2h^2 + h^2 {\rm cosec}^2\, \alpha - 2\sqrt2\, h^2\, {\rm cosec\,} \alpha \cos\theta Equating and dividing out by h^2 (the height cannot be zero)...
  16. fan96

    Polynomials

    Are those not triple roots?
  17. fan96

    Polynomials

    I'm having some trouble with part (h). If one of the non-real roots had real part k , then by the complex conjugate root theorem, the sum of the two non-real roots should be 2k . Then, using the sum of roots, the last root should be k . But (k,\,P(k)) is the point of inflection of...
  18. fan96

    Polynomials

    I didn't address those because they seemed trivial to me - my bad. If k is positive, then k + \sqrt{k^2-1} must be positive since two positive numbers are being added. If k is negative, then k - \sqrt{k^2-1} must be negative too since a positive number is being subtracted from a...
  19. fan96

    Polynomials

    a) Consider the graph of y = P(z) on the cartesian plane, for real z . P(0) = -k P'(z) = 3(z^2-2kz+1) P'(0) = 3 P'(z) = 0,\, z = k \pm \sqrt{k^2-1} (Note that we require |k| \geq 1 for a turning point to exist - otherwise P(z) has exactly one real root) We will prove that...
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