# Differential Equations

Discussion in 'Math' started by evo21, Jan 3, 2008.

1. ### evo21 Thread Starter New Member

Nov 17, 2007
5
0
hey,
i have a big test coming up and i need to study something but i dont know how its called in english.

its the inverse of differential, something that transforms the differential equation in the original equation, like:
[cos(x)] = sen(x) or [1] = x

and where can i find books talking about that?

2. ### shankbond Active Member

Nov 4, 2007
53
0
i think u r either talking about
differential equations or integration calculus
so , search books mentioning the above said titles

3. ### Papabravo Expert

Feb 24, 2006
10,170
1,797
I can't make any sense of your request.

My best guess is that you are talking about the Laplace Transform. It transforms a differential equation into an algebraic equation. Is that what you are talking about?

4. ### evo21 Thread Starter New Member

Nov 17, 2007
5
0
f'(cos x)= -sen x

if i want to reverse it

[-sen x] = cos x

what is the name of that operation?
in my country it is called primitivate, but i cant find anything with that name, so i was wondering what is the proper name in english..

5. ### Dave Retired Moderator

Nov 17, 2003
6,960
145
The inverse of differentiation is integration - see the Fundamental Theorum of Calculus.

What you have done in the above post is integrate the original differential function.

Dave

6. ### Papabravo Expert

Feb 24, 2006
10,170
1,797
I see it now. What threw me was the use of the abreviation "sen" for the sine function. The "English" abreviation is sin, as in sin(x).

Some textbooks also call the operation the anti-derivative, but I'm not sure the useage is widely accepted.

You might find the table from the following article handy. Google and Wiki are your friends.

http://en.wikipedia.org/wiki/Trigonometric_function

Nov 17, 2003
6,960
145
8. ### evo21 Thread Starter New Member

Nov 17, 2007
5
0
yeah thats it. in my school we first learn the anti-derivatives and only after we learn the integration, so i though they were different. my teacher uses a different notation for anti-derivatives that doesnt look like integration at all, hence the confusion.