Classify the equations as: Ordinary or Partial, order, degree, variables, linear or nonlinear
1)
dy
= cos x
dx
2)
d2y
+ k 3y = 0
dx 2
or y'= cos x
or y!! + k 3 y = 0
3) (x 2 + y 2 )dx = 2xdy
4)
!u
!2u !2u
= h2 ( 2 + 2 )
!t
!x !y
!2w !w
+
=0
5)
!x 2 !y
! d 2s $ 6
ds
6) # 2 & ' xy + s = 0
dt
" dt %
7)
d3x
dx
+ x = 4xy
3
dy
dy
3
d5y
! dy $
+ x # & ' 8y = 0
8)
5
" dx %
dx
d2y
d2x
9) 2 + x 2 = x
dt
dt
10) x
!f
!f
+ y = nf
!x
!y
11) L
d 2u
du 1
+ R + u = E cost
2
dt
dt c
12) cy!!! + my!! " y = 6