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    Second Derivative Help

    It can – consider y = x^5 at the origin.
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    S1/17 WAM Predictions

    The total of n integers will have a remainder of either 0, 1, 2, 3, …, or (n-1) upon division by n. This implies that the possible fractional parts for the average of n whole numbers are just: 0, 1/n, 2/n, 3/n, …, (n-1)/n. E.g. If 1 subject: only can have decimal of 0. If 2 subjects: only can...
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    MATH2601 Higher Linear Algebra

    $\noindent Note that if $\lambda$ is an eigenvalue of $Q$ with unit eigenvector $\vec{v}$, then$ $$\begin{align*}\lambda &= \lambda\left\langle \vec{v},\vec{v}\right\rangle \\ &=\langle \lambda\vec{v},\vec{v}\rangle \\ &= \langle Q \vec{v},\vec{v}\rangle \\ &= \langle \vec{v},Q^{*}...
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    VCE Maths questions help

    Note f'(x) = 5 for all x, so f'(1) = 5.
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    MATH2601 Higher Linear Algebra

    Well you wrote one up here before, so maybe you'd find that easiest to "memorise" for yourself: Note that it needs to be adapted slightly to deal with the complex case, but it's not too big a deal. You can also probably find many proofs online. There are twelve proofs here, but they seem to...
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    MATH2601 Higher Linear Algebra

    Hint: Use the axioms to show that a + a0 = a.
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    Anyone ready for UMAT?

    B (as I said in my first line)
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    Anyone ready for UMAT?

    Answer: B tells the complete lie. Assume C tells the complete truth (so B and C are the two who did it). Then we can see that: • B must be telling the complete lie (since neither D nor A did it, yet B says these two did it) • A and D both tell half-truths (each identifies precisely one of the...
  9. I

    String tension question

    Let the tensions be T1 and T2, and obtain two simultaneous equations by decomposing forces in the horizontal and vertical direction (using right-angle trigonometry), and using that the acceleration in each of these directions should be 0 (assuming we are in equilibrium).
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    MATH2111 Higher Several Variable Calculus

    Also the first term on your RHS has a mistake/typo (shouldn't have y).
  11. I

    MATH2111 Higher Several Variable Calculus

    Also, if V is a subset of U, then f(V) is automatically a subset of f(U) (true for any function and sets (that make sense)). (Or maybe you meant that it doesn't state that f(V) is open.)
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    MATH2111 Higher Several Variable Calculus

    Generally this is correct, but consider the implications of f being an invertible (locally) continuous map.
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    MATH2111 Higher Several Variable Calculus

    What have you tried so far? Did you try maybe considering the inverse function theorem?
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    MATH2111 Higher Several Variable Calculus

    $\noindent Have you tried using the chain rule?$
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    First Year Mathematics A (Differentiation & Linear Algebra)

    $\noindent We can show this using a limit comparison test and the $p$-test. $\Big{(}$Note that the integrand is continuous on $[0,\infty)$ and is asymptotically equivalent to $\frac{1}{x^{\frac{\alpha}{2}-2}}$ as $x\to \infty$, for $\alpha > 0$.$\Big{)}$$
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    MATH2901 Higher Theory of Statistics

    We don't know it ("it" refers to the population standard deviation (or really the standard deviation of the assumed underlying distribution)), since that's only the sample standard deviation.
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    MATH2901 Higher Theory of Statistics

    Oh yeah, I forgot to include the n in front of the matrix when getting the 1,1 entry of the inverse. It should be n in the denominator indeed (for final answer).
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    MATH2901 Higher Theory of Statistics

    It depends on the hypothesis test and the situation at hand. Common ones are when you have asymptotic normality under a null hypothesis (which is often the case from the Central Limit Theorem), you can use a Z-test ( https://en.wikipedia.org/wiki/Z-test ), or you could use a Chi-Squared test...
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    MATH2901 Higher Theory of Statistics

    Also I think the final answer's denominator should be n^2 (not n).
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