ATAR Notes: Forum

VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: PB on June 22, 2013, 08:09:42 pm

Title: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: PB on June 22, 2013, 08:09:42 pm
My teacher said that lets say if you are solving DE we should always express the solution with the top term as the subject. So if solving dh/dt, the solution should always be reshuffled so as to be expressed as h in terms of t(if neccessary)  Is this true?
Because for the answers for Essentials Ex 9E Q2a states it as t in terms of h...so yeh..bit confused :P
Thanks! +1
Title: Re: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: lzxnl on June 23, 2013, 06:07:44 pm
Give your teacher the differential equation 55e^y*sin(y)*cos^3(y) dy/dx = x^3+3x-5 and he/she will eat their words :P

It depends on the question; if it asks for h in terms of t, then you give h in terms of t. Generally they'll do so, but if they just ask you to solve the equation...you have technically solved the differential equation by removing the derivative term.
Title: Re: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: PB on June 23, 2013, 07:21:13 pm
Ah I see, thks nliu! its amazing how much you know!! Have you already finished the course??
Title: Re: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: lzxnl on June 23, 2013, 09:51:00 pm
No worries! And that's certainly an exaggeration; what have I done to suggest that I know an unusual amount? I've just presented you a weird differential equation :P

Although yes I have finished the course. I figured that finishing the course earlier on would help reduce my workload this year.
Title: Re: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: PB on June 23, 2013, 10:40:42 pm
Haha, just the general confidence you exude from answering questions on the forums lead me to that inference.
and its a wise smart decision you made, wish I thought of that last year :PP
Title: Re: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: lzxnl on June 23, 2013, 11:08:40 pm
Oh it's funny; I'm considered a nerd by others when I do the course early, but when others get to the spesh course...

And I exude confidence when answering questions? Well that's something I have to moderate :P
Title: Re: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: Lasercookie on June 23, 2013, 11:23:17 pm
Quote from: nliu1995 on June 23, 2013, 11:08:40 pm
And I exude confidence when answering questions? Well that's something I have to moderate :P
I think he meant confidence in a good sense :3
Title: Re: When solving DEs, do we always have to express it with the top term as the sbjt?
Post by: Stick on June 28, 2013, 02:33:17 pm
Quote from: PB on June 22, 2013, 08:09:42 pm
My teacher said that lets say if you are solving DE we should always express the solution with the top term as the subject. So if solving dh/dt, the solution should always be reshuffled so as to be expressed as h in terms of t(if neccessary)  Is this true?
Because for the answers for Essentials Ex 9E Q2a states it as t in terms of h...so yeh..bit confused :P
Thanks! +1

I got told the same thing and we've had to do it for more difficult problems as well... :S