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  1. BubblesAreUs

    Catenary problem

    Homework Statement Suppose we have a rope of length L and total mass M. Suppose we x its ends at points (xA; yA) and (xB; yB). We want to determine the shape the rope makes, hanging under the influence of gravity. The rope is motionless, with a shape parametrised by y(x) or equivalently, x(y)...
  2. BubblesAreUs

    Algebra Textbook for Abstract Algebra / Group Theory

    I am looking for an accessible textbook in group theory. The idea here is to use it to learn basic group theory in order to take up Galois Theory. My background includes Calculus I-IV, P/Differential Equations, Discrete Mathematics including some graph theory, Linear algebra, and am currently...
  3. BubblesAreUs

    Determine whether the subset is a vector subspace

    Homework Statement Recall that F is the vector space of functions from ℝ to ℝ, with the usual operations of addition and scalar multiplication of functions. For each of the following subsets of F, write down two functions that belong to the subset, and determine whether or not the subset is a...
  4. BubblesAreUs

    Schools Low cost distance education universities

    Hello all, I'm enrolled at an Australian university that offers mathematics. However, I want to fast track my education by enrolling in units over the holidays ( late Nov to early March). The problem, however, is that my institution does not offer advanced second or third year units. I'm...
  5. BubblesAreUs

    Importing survey on R Studio

    I am using R studio for a practical and I need to load a survey. It suggests that I place the following into the R template that I was provided: survey=read.csv("http://www.maths.usyd.edu.au/u/UG/IM/STAT2012/r/survey.csv") attach(survey) pulse.sf=pulse[smoke==1 & sex==2] pulse.sf Template...
  6. BubblesAreUs

    MATLAB Modelling Question

    Homework Statement Modelling the following equation: k = Delta Q / t Homework Equations Q = T2 - T1 = -40 (fixed) t = Delta Q / k. I need to find t. k can be floating so I suppose 0 to 10 minutes with 0.5 increments The Attempt at a Solution I don't have MATLAB on me at the moment...
  7. BubblesAreUs

    Set Theory? question

    Homework Statement Let f: X ----> Y and g: Y ----> Z be functions and let h = g o f: X ----> Z Homework Equations a. If h is surjective then g is surjective b. If h is surjective then f is surjective. The Attempt at a Solution Here h: X ----> Z a. Suppose h: x ---> z is surjective...
  8. BubblesAreUs

    Floating point numbers

    I'm finding it difficult to find the exact value of epsilon on python? Moreover, I am also supposed to find the smallest floating point number as well. Wikipedia tells me that the machine epsilon is 2−52 ≈ 2.22e-16 for 64-bit IEEE 754 - 2008? Is this the exact value on Python? Outside of...
  9. BubblesAreUs

    LU factorisation

    Homework Statement Let A = 4 -4 -1 4 -4 0 4 0 0 Use the criterion from the lectures to show that A does not have an LU factorisation such that A = LU with lower and upper triangular matrices L and U. How can you re-arrange the matrix rows...
  10. BubblesAreUs

    MATLAB question ( plot)

    Homework Statement Plotting the exponential exp(-cx), 0 ≤ x ≤ 1 with c = 1, 2, 3, 4. Use a for loop. Homework Equations The Attempt at a Solution for c = 1:1:4; for x = 0:1; F = exp(-cx); end end plot(x,F) I'm not really sure where to start.. Help is appreciated.
  11. BubblesAreUs

    Comp Sci Python problem: Plotting two functions against each other

    Homework Statement Enter a minimum height and velocity into plot function and return a velocity-height plot. Homework Equations The Attempt at a Solution # Find length of general list n = len(K) # Build a list for time [0,20] seconds ( Global) time = n*[0.0] # Acceleration of gravity g =...
  12. BubblesAreUs

    Depth and pressure in a submarine

    Homework Statement As a submarine dives, the pressure on its hull.. a. remains constant b. increases c. depends on the decrease in volume of the submarine d . decreases e. depends on the thickeness of the walls of the submarine Homework Equations P = F / A The Attempt at a Solution Not a...
  13. BubblesAreUs

    Investigating real-world situation

    Homework Statement Analyse the physical world around you in terms of Circular Motion/ Energy/ Momentum / Pressure/ Buoyancy/ Bernoulli's Equation. Choose one aspect you would like to investigate further. Homework Equations e.g. why some potatoes float and other do not The Attempt at a...
  14. BubblesAreUs

    C/++/# Calling C function on *nix terminal

    Code: #include <stdio.h> #include <stdlib.h> int main() { return EXIT_SUCCESS; } float minimum( float x, float y) { if (x < y) return x; else return y; } /Code How does one call out...
  15. BubblesAreUs

    Finding the two closest values of a given value

    Homework Statement Say, I was given a list, i.e. [1, 3, 7, 9, 12, 15, 24] Now I'd like to find two values closest to an input ( say, x) so that I can produce an interval ( f(a), f(b)). This interval would be used in an IVT problem where the intervals will be be part of [a,b] and will be...
  16. BubblesAreUs

    Lower Bound of given pair.

    Since I'm not sure if posting assignment questions is allowed, I'm just going to ask specific questions just to be safe. 1. Homework Statement Find all the lower bounds of given pair. Say (a, b) in T. Homework Equations Proof for greatest lower bound: ∀g,a,b ∈ T ⇔ ( g ≺ a) ^ (g ≺ b) ^ (...
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