<p>I'm looking into how the Lambert solution works but there's one bit I'm stuck on. From Wikipedia's <a href="https://en.wikipedia.org/wiki/Lambert%27s_problem#Initial_geometrical_analysis" rel="nofollow noreferrer">Lambert's problem; Solution for an assumed elliptic transfer orbit</a> (starting at Eq. 11):</p>
<p><a href="https://i.sstatic.net/zTHlX.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/zTHlX.png" alt="enter image description here" /></a></p>
<p>I don't understand how we can draw the conclusion that <span class="math-container">$x_0$</span> is proportional to <span class="math-container">$r_m$</span> let alone this value. Any explanation would be appreciated.</p>

CC BY-SA 4.0
2022-07-24T20:18:21.420Z
I see you've included a little bit of [MathJax](https://math.meta.stackexchange.com/q/5020/284619); it's strongly discouraged to use screenshots of math and text for several reasons, could you write out the material in your image as MathJax as well? Thanks, and *welcome to Stack Exchange!*
uhoh
CC BY-SA 4.0
2022-07-24T20:20:12.400Z
Also, don't worry if this question is closed as off-topic here in Astronomy SE. While it's not about Astronomy *per se*, it is certainly completely on-topic in [Space Exploration SE](https://space.stackexchange.com/) and may be migrated there. There are [almost 200 different SE sites](https://stackexchange.com/sites#questionsperday) to choose from!
uhoh
CC BY-SA 4.0
2022-07-24T20:22:27.410Z
I’m voting to close this question because it's a question about transfer orbits which is not about Astronomy as defined in the help center. However, it is certainly on-topic in Space Exploration SE and a great candidate for speedy migration.
uhoh
CC BY-SA 4.0
2022-07-25T06:41:25.347Z
You've found one of many Wikipedia articles that are terribly written. The article does however have references.
David Hammen
<orbital-mechanics><eccentric-orbit>
Confused about the derivation of the x co-ord of the focus in the Lambert solution?
mathPhys
# Confused about the derivation of the x co-ord of the focus in the Lambert solution?

(Asked by: username_0 on 2022-07-24)

I'm looking into how the Lambert solution works but there's one bit I'm stuck on. From Wikipedia's [Lambert's problem; Solution for an assumed elliptic transfer orbit](https://en.wikipedia.org/wiki/Lambert%27s_problem#Initial_geometrical_analysis) (starting at Eq. 11):

[![enter image description here](https://i.sstatic.net/zTHlX.png)](https://i.sstatic.net/zTHlX.png)

I don't understand how we can draw the conclusion that $x\_0$ is proportional to $r\_m$ let alone this value. Any explanation would be appreciated.

**Tags:** orbital-mechanics, eccentric-orbit

> **Comments:**
> **username_1**: I see you've included a little bit of [MathJax](https://math.meta.stackexchange.com/q/5020/284619); it's strongly discouraged to use screenshots of math and text for several reasons, could you write out the material in your image as MathJax as well? Thanks, and *welcome to Stack Exchange!*  
> **username_1**: Also, don't worry if this question is closed as off-topic here in Astronomy SE. While it's not about Astronomy *per se*, it is certainly completely on-topic in [Space Exploration SE](https://space.stackexchange.com/) and may be migrated there. There are [almost 200 different SE sites](https://stackexchange.com/sites#questionsperday) to choose from!  
> **username_1**: I’m voting to close this question because it's a question about transfer orbits which is not about Astronomy as defined in the help center. However, it is certainly on-topic in Space Exploration SE and a great candidate for speedy migration.  
> **username_2**: You've found one of many Wikipedia articles that are terribly written. The article does however have references.  

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