5,798 reputation
11323
bio website jpmccarthymaths.com
location University College Cork, Ireland
age 29
visits member for 3 years, 1 month
seen 37 mins ago

An assistant lecturer at the Cork Institute of Technology. I am also a PhD student of mathematics at University College Cork, Ireland. I hold a BSc and an MSc from UCC. A recent cv, (June 2014) may be found here.

https://jpmccarthymaths.files.wordpress.com/2010/07/resume.pdf


6h
comment What is my maths score as a percentage?
What material was the module on?
13h
comment Solving system of differential equations $\dot{x}=3x - 2y$, $\dot y = 2x - y + 15 e^t \sqrt{t}$
@Did ...I thought at the time that it would be amenable to those methods...
2d
comment Solving system of differential equations $\dot{x}=3x - 2y$, $\dot y = 2x - y + 15 e^t \sqrt{t}$
Do you know any Laplace Transforms?
Dec
11
answered How does Wolfram Alpha come up with the substitution $x = 2\sin u$? Integration/Analysis
Dec
11
comment Finding the hypotenuse of Right Angle Triangle
You can write $12\sqrt{2}\approx 16.97$ or $12\sqrt{2}\approx 16.9705627485\approx 16.97$ or maybe $12\sqrt{2}=16.9705...\approx 16.97$. It is incorrect to write $12\sqrt{2}=16.9705627485$.
Dec
11
comment Finding the hypotenuse of Right Angle Triangle
Do you want to change the very last equals sign? It should be an $\approx$ sign because $12\sqrt{2}$ is not equal to 16.97...
Dec
11
revised Finding the hypotenuse of Right Angle Triangle
deleted 2 characters in body
Dec
10
revised Differentiate $y=\frac 1 x$ from first principles
added 4 characters in body
Dec
10
comment Differentiate $y=\frac 1 x$ from first principles
@user3764899 It does. Do you understand the $\mathcal{O}(x)$ notation I am using? It just means terms of the form $a_1x+a_2x^2+a_3x^3+\cdots$.
Dec
10
revised Differentiate $y=\frac 1 x$ from first principles
added 24 characters in body
Dec
10
comment Differentiate $y=\frac 1 x$ from first principles
Eh, why the downvote?
Dec
10
answered Differentiate $y=\frac 1 x$ from first principles
Dec
10
answered Existence of a approximate unit $U_{n}^{2}$ for a $ C^{*}$-algebra $
Dec
10
revised Equation Of A Straight Line Passing Through A Point and Having an Intercept
added 533 characters in body
Dec
10
answered Equation Of A Straight Line Passing Through A Point and Having an Intercept
Dec
9
comment Explain why $|x^2-x|$ is not differentiable at $x=1$
Sketch $x^2-x$ and hence $|x^2-x|$ to understand why it isn't differentiable.
Dec
9
awarded  Caucus
Dec
3
comment matrix coefficients are representative functions.
By the sounds of it it was done a few pages previously.
Dec
3
comment Finding unique solutions
At the start the distance between the graphs is one... it reduces to zero at the intersection and then goes negative at $x=\pi/2$. To show it rigourously... well do you know calculus --- that would be the easiest? It is not hard to show that $y=kx$ is increasing and to show that $y=\cos x$ is decreasing use the formula for $\cos(A+B)$.
Dec
3
answered Solving a 2nd order ODE & phase lag computation