Capacitor polarity confusion in a circuit
Logically interpret it as non-polar but practically when chooosing a part Vin- = Vin+=0V so if an e-cap (polar) was used on a single supply, it's + polarity would be on the output.

Some old drafting std's use this symbol for all caps polar or not so dont be confused.  A polarized cap in America shud have the + symbol. EU , ISO and IPC stds may be different.  ( I foget which is most current std but your location, company and mileage may vary)

This academic question just shows it backwards to conventional symbols.