Monday, July 25, 2011

late night revelation whilst doing physics about maths

ok. this is deep, from a 2 unit perspective, especially one taught by the teacher we have (no name-dropping)

so you know how the symbol for differentiation, which finds the gradient, is dy/dx?
its the change in y / the change in x
this is equal to the gradient formula, y2-y1 / x2-x1

also if you take like, for example y = 4x
using differentiation we can immediately find
y' = 4

do it manually:
at x=1, y=4
at x=2, y=8
m = 8 - 4 / 2 - 1
= 4/1
=4

and then in integration because its the reverse of differentiation, you times it by dx instead of dividing it by. thats what the dx on the end is

yeah, its 1 am.

5 comments:

Brian said...

Wait what?

Explain with an example with your dx multiplication logic.

Hoggle said...

integration is the (dy/dx)dx
so essentially y.
to put it another way
integration is the integral of y*dx;
eg.
as 1/x=dx/dy
x=dy/dx
dy=x.dx
y=x.dx
or the integral of x essentially as x is the derivative.
If that makes sense.

Hoggle said...

* and . are times by the way

Lord of the Palmtrees said...

yeah i know. i realised that like months ago.

Brian said...

Surprisingly, even after a semester of having two maths subjects, I haven't done a single bit of integration.