Search results

The question uses crystalline oxalic acid (aka oxalic acid dihydrate) as a primary standard. This comes in the form (COOH)2.2H2O Apparently, his teacher said to include the 2 H2O in the molar mass for the calculations, while his chem tutor said not to. Which obviously makes a difference in...

^ In how many ways can five students be placed in three distinct rooms so that no room is empty? Please demo, thanks

Since logic is obviously not taught, I was wondering if in the exam... Would working backwards with \Leftarrow (implied by) cost marks?

(a) Calculate the molarity of a solution prepared by dissolving 0.345 g calcium chloride in enough water and diluting to 250.00 mL. (2 marks) The answer to this part is 0.0124 mol L-1 at 3 s. f. Just use the rounded answer for convenience please. (b) What is the concentration of the...

When reciprocating, local max become local min and vice versa. Do increasing horizontal points of inflexion remain increasing? Or do they become decreasing. Edit: Still need confirmation on if this holds in general please. Using GeoGebra I have found that the HPOI does reverse for y=x^3+1

This probably has been asked but I don't recall so I'll just post here for now. Topic: That mathematics was discovered, not invented. Give reason(s) to support your argument. Edit: If it turns out I've asked this before please just link me to the post if you find it lol

How would you tackle integrals of the form \int \sec^m{x}\tan^n{x}\,dx where m is odd and n is even? (Within the scope of MX2)

(Sorry, post remade because I made a massive error) How would you prove that this is false from the definition? (i.e. proof by contradiction or something similar) \lim_{x\to \infty}{x^{-2}}=1 _____ $So the definition says $\forall \epsilon > 0 \exists M $ such that $x>M \implies...

Was helping out a friend with it but for the last part, I was wondering if there was a shorter method? Q: You have the hyperbola xy=16 a) Sketch + indicate where the hyperbola intersects its axes of symmetry So (±4,±4) b) Consider P(4p,4/p), Q(4q,4/q) where p,q>0 Then the chord PQ has equation...

I think this question may be asking me to construct a proof so I don't want to quote the CLT or anything $b) Let $X_1$ have a Poisson distribution with mean $\lambda_1$ and$ X_2$ with $\lambda_2$. Using the result of (a) or otherwise, show that $\\ P(X_1+X_2=n)=p_n(\lambda_1+\lambda_2)...

I just want to check my method $Q: Use Leibniz's rule to differentiate both sides of the equation$\\ \int^x{\left(a^2+x^2\right)^{-\frac{1}{2}}dx}=\sinh^{-1}{\frac{x}{a}}+c\\$ with respect to $a$. Hence find a formula for $\int{\left(1+x^2\right)^{-\frac{3}{2}}dx} (The question put that...

What even is this exponential distribution question getting at? $Q: For the situation of Exercise 39 find the probability of there being a 50 year gap between 'once in a hundred years' floods$ (This was Q39 - a Poisson discrete R.V. question) $The number of 'once in a hundred years' floods can...

Is there a higher dimensional implicit differentiation hax (sorry I'm doing maths whilst being a bit hyper) to get me a shortcut for this question $Find the tangent planes and normal lines to the following surfaces at the points indicated: \\ d) $x^2+y^2+z^2=3$ at the point $(1,1,1) Or should...

Trying to calculate the variance of the uniform distribution and I don't know what the trick is to simplify the horrible looking sum \sigma^2\\ = \mathbb E \left[{(X-\mu)}^2\right]\\= \sum_{k=1}^n{p_k{(k-\mu)}^2} $where $p_k=\frac{1}{n}$ and $\mu=\frac{n+1}{2} edit: wait I just realised I...

Your high school life may have been a lie http://www.iflscience.com/plants-and-animals/first-eukaryote-found-lack-mitochondria

This supposedly really hard question with a total of five parts + no answers starts off with $a) Estimate the error in the Simpson's rule approximation$\\ e^{\frac{1}{k}}-e^{-\frac{1}{k}}=\int_{- \frac{1}{k} }^{\frac{1}{k}}{e^tdt}\approx...

Feeling like I may have unnecessarily overcomplicated this question just to get the right answer. Would appreciate advice on if there is a shorter method. (I think I am required to use set notation.) $Q: A brewery brews one tpe of beer which is marketed under three different brands. In a...

$Question: Does $\int_{-\infty}^{\infty}{\frac{x}{1+x^2}dx}$ converge? Explain.$ The answer is obviously that it does not, but I want to check if my proof is flawed. $Suppose $f(x)=\frac{x}{1+x^2}$ and $g(x)=\frac{1}{x}$. Now, \\ $\lim_{x\rightarrow \infty}{\frac{f(x)}{g(x)}}=\dots=1 $And...

What does this question actually mean? $Find the limits of the sequences whose $n$th terms are:\\ a)$ \frac { {1}^{ a }+ {2}^{ a }+\dots + {n}^{ a } }{ {n}^{ 1+a } }\quad (a>1)\\$b) $\frac{1}{2n+1}+\frac{1}{2n+2}+\dots+\frac{1}{3n}

\\$Prove that $|A\textbf{x}-\textbf{y}|$ is least when $\textbf{y}-A\textbf{x}$ is orthogonal to $\sigma=$span(columns of $A).