Question

what is the order of this DE

Answer 1

\[\frac{ d^6y }{ dx^6 }\frac{ d^4y }{ dx^4 }=y^5\]

Answer 2

i would think its 24 but im not sure

Answer 3

I think it's the same as polnomials, you add the powers. So 6+4.

Answer 4

oh

Answer 5

Not 100% sure though but i think that's what it is.

Answer 6

\[\frac{ dy }{ dx }=\frac{ d^6y }{ dx^6 }\]

what about this

Answer 7

i'm thinking 5

Answer 8

order is the highest derivative

Answer 9

because u treat them as fractions

Answer 10

its a differential equation, not a fraction...

Answer 11

i know that..but still

Answer 12

\[y^{(6)} = \frac{d^6y}{dx^6}\]
y^6 is the 6th derivative with respect to x

Answer 13

ohhh

Answer 14

right

Answer 15

i should do it like that then cheers

Answer 16

yea the other one is 6 not 5 then

Answer 17

no clue about the first question

i dont know the rules for multiplying derivatives, rather i dont remember them

Answer 18

@agent0smith, regarding the first equation, the powers don't work like they do for polynomials.
\[y^{(3)}y^{(4)}\not=y^{(7)}\]
(For \(y\not=C\), that is.)

Answer 19

yea the first was not 10 rather 6

Answer 20

No, i get that @SithsAndGiggles, but what about the order? A polynomial \[\Large y^3 x^5 +y^2x^3\]like this has a degree of 8... i don't remember if it works the same for DE's though.

Answer 21

Ah, well it doesn't work for DEs as far as I can tell.

Answer 22

I feel like it doesn't, since the highest derivative is still 6th, but... idk..been a long time since i've needed to know it. From @chris00 it seems like it doesn't work the same as polynomials.

Answer 23

yea. least this question was a good refresher haha

Answer 24

but thanks everyone

Answer 25

place derivatives in parenthesis

so it can be differentiated from powers