# Unable to solve for variables with subscripts [closed]

ΔF = 0.0025;
P = Quantity[8, "Days"];


When I solve for Rp all works great:

Subscript[R, s] = Quantity[0.8, "SolarRadius"];
ΔF = 0.0025; (*Transit depth*)
Solve[{Rp^2/Subscript[R, s]^2 == ΔF, Rp > 0}, Rp, Reals ]


but when I solve for a variable with a subscript (Subscript[R, p] instead of Rp), Mathematica finds no solution:

Subscript[R, s] = Quantity[0.8, "SolarRadius"];
ΔF = 0.0025; (*Transit depth*)
Solve[
{Subscript[R, p]^2/Subscript[R, s]^2 == ΔF, Subscript[R, p] > 0},
Subscript[R, p], Reals ]


Is there any way to avoid this and treat variables with subscript as normal (separate) variable names?

Interestingly, Mathematica seems to have no problem when, for example, a is given a subscript. It's only an issue when the variable that I solve for has a subscript.

• With 11.1.1 for Mac OS X x86 (64-bit) (April 27, 2017) everything works as expected Jan 1, 2021 at 12:28
• Don't use subscripts, you will be better of with regular variables. Jan 1, 2021 at 12:32
• I have to agree with yarchik though. Don't use subscripts, or at least only use them for display purposes. You'll find the same advice in many questions on this site. A Subscript expression is not a Symbol and there are lots of parts of the language which don't work properly when you use subscripts instead of symbols for your variables. Jan 1, 2021 at 13:18
• Good practice is to avoid variable that start with capital letter. Jan 1, 2021 at 22:27
• I’m voting to close this question because the problem the OP is experiencing cannot be reproduced; I suspect it is being caused by corrupted lexical elements in the OP's Mathematica notebook. Jan 2, 2021 at 4:42