Fixed a formula and changed R to degR (#2498)
Fixed a formula and changed R to degR (#2498)

Changed `R` to `degR` as there is no unit `R`

`math.createUnit('mile', '1609.347218694', {override: true}})` has a syntax error (an extra `{` ) and is missing units, changed it to `math.createUnit(('mile', '1609.347218694 m', {override: true})` as I think was the original intention.

Co-authored-by: Jos de Jong <59a98748561b5cb9fc928afd2763d3591de2155c@gmail.com>
FSMaxB/mathjs,josdejong/mathjs,josdejong/mathjs,josdejong/mathjs,FSMaxB/mathjs,FSMaxB/mathjs,FSMaxB/mathjs,FSMaxB/mathjs,josdejong/mathjs,josdejong/mathjs