# How to solve higher order differential equations using DifferentialEquations.jl

**URL:** <https://discourse.julialang.org/t/how-to-solve-higher-order-differential-equations-using-differentialequations-jl/90915>\
**Category:** New to Julia\
**Tags:** package\
**Created:** [November 27, 2022, 7:42pm UTC](https://discourse.julialang.org/t/how-to-solve-higher-order-differential-equations-using-differentialequations-jl/90915 "2022-11-27T19:42:39Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![GottDengDirk](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gottdengdirk/32/43952_2.png) [@GottDengDirk](https://discourse.julialang.org/u/GottDengDirk)\
**Post date:** [November 27, 2022, 7:42pm UTC](https://discourse.julialang.org/t/how-to-solve-higher-order-differential-equations-using-differentialequations-jl/90915/1 "2022-11-27T19:42:39Z")

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Hi,  
I can only solve second order differential equations with ODEProblem. I would like to know how to define higher order differential equations.  
dddx+0.12_ddx+39.48_dx+4.73741\*x=4.73741

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**Author:** ![Oscar\_Smith](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oscar_smith/32/25343_2.png) [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)\
**Post date:** [November 27, 2022, 7:45pm UTC](https://discourse.julialang.org/t/how-to-solve-higher-order-differential-equations-using-differentialequations-jl/90915/2 "2022-11-27T19:45:49Z")

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Higher order diffeqs can always be written as 1st order by introducing more variables.

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [November 28, 2022, 12:47pm UTC](https://discourse.julialang.org/t/how-to-solve-higher-order-differential-equations-using-differentialequations-jl/90915/4 "2022-11-28T12:47:11Z")

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And ModelingToolkit.jl can automate this transformation, so I’d recommend it. Just define the equation you have here and do `structural_simplify` to generate the extended form.