# How to solve nonlinear equations?
**URL:** https://discourse.julialang.org/t/how-to-solve-nonlinear-equations/80426
**Category:** New to Julia
**Tags:** question
**Created:** [May 3, 2022, 1:39pm UTC](https://discourse.julialang.org/t/how-to-solve-nonlinear-equations/80426 "2022-05-03T13:39:34Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@tugce](https://discourse.julialang.org/u/tugce)
#### Post date: [May 3, 2022, 1:39pm UTC](https://discourse.julialang.org/t/how-to-solve-nonlinear-equations/80426/1 "2022-05-03T13:39:34Z")
I am trying to find the y variable in this problem: H = 0.5\*(x^2+y^2)+y\*x^2-(y^3)/3. H values change between 1/20:1/2, and x values change -2:2. I tried to calculate every y value in these conditions but I couldn’t. How can I solve it?
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### Author:  [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [May 3, 2022, 1:42pm UTC](https://discourse.julialang.org/t/how-to-solve-nonlinear-equations/80426/2 "2022-05-03T13:42:47Z")
That’s just a (cubic) polynomial in y, so you could use any package for polynomial roots, e.g. [PolynomialRoots.jl](https://github.com/giordano/PolynomialRoots.jl) or [Polynomials.jl](https://github.com/JuliaMath/Polynomials.jl).
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### Author:  [@ctkelley](https://discourse.julialang.org/u/ctkelley)
#### Post date: [May 3, 2022, 1:59pm UTC](https://discourse.julialang.org/t/how-to-solve-nonlinear-equations/80426/3 "2022-05-03T13:59:30Z")
There’s always the old-fashioned way
[https://math.vanderbilt.edu/schectex/courses/cubic/](https://math.vanderbilt.edu/schectex/courses/cubic/)
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### Author:  [@tugce](https://discourse.julialang.org/u/tugce)
#### Post date: [May 7, 2022, 4:11pm UTC](https://discourse.julialang.org/t/how-to-solve-nonlinear-equations/80426/4 "2022-05-07T16:11:00Z")
Thank you, these were useful for me. I understood my problem better.