query on where condition - upper(rtrim(column)) = ?

Hi,

I have a table StudentGrades. This table has an index on the column "grade" of type varchar2.
The values of "grade" column contain string values like: 'A', 'a', 'A ', 'a ', 'A ', i.e. mixed cases and containing white spaces at times.

If I run a query below, will it use the index on grade?

select * from StudentGrades where upper(rtrim(grade)) = ?

where ? is an input parameter from the program and the value has been trimmed and converted to uppercase.

Thanks,
Jason