# Search results

1. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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) ^ (...