Question: probably my problem i´m gonna ask seems ridiculous and quite basic.
I want to solve an equation with the following code, where a,b,c are parameters. But surprisingly they don´t appear in the solution. I guess, it´s my mistake but I don´t see what I have done wrong. For a quite similiar equation it worked quite well and they didn´t disappear. So here is my line:

```
DSolve[Derivative[1][r][t] == a*exp (-(b - (c*1/r[t])^0.5)), r[t], t]

```

Additionally, I wanted to know if there´s a easy way to get an parametric plot.
I would be very grateful if someone could give a hint!

Cheers!

Answer: 
Since it hasn't been proposed yet:

```
Inner[UndirectedEdge, {a, b}, {{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}}, Sequence]

```

> 
> 
> ```
> {a <-> 1, b <-> 6, a <-> 2, b <-> 7, a <-> 3,
>  b <-> 8, a <-> 4, b <-> 9, a <-> 5, b <-> 10}
> 
> ```
> 
> 

(You did say that "I don't care (about) the ordering of its elements"! ;))
As per request:

```
Join@@ MapThread[Thread[#1 <-> #2] &, {{a, b}, list}] 

```

`Flatten` or `Catenate` to flatten list result from `MapThread`.

See comment by Kuba below.