Which wire is negative on this PC fan? - Electrical Engineering Stack Exchange

I just got this PC fan and it has a 3 pin connector, I know the wire with the white stripe is positive but how can I find out which of the other two wires are negative? If you can't see the photo

Driver Recovery Products 2-4 Gauge Battery Quick Connect/Disconnect (2 Pack) 175 Amps Wire Harness Plug for Winch or Trailer : Automotive

raspberry pi - What does short circuiting a RST front IO header do? - Electrical Engineering Stack Exchange

controller - H-bridge/buck converter with negative and positive voltage range - Electrical Engineering Stack Exchange

DAYONE Pull Chain Switch Zing Ear ZE-109 Ceiling Fan Switch Ceiling Fan Light Lamp Replacement 3 Pack Bronze

power - How do I tell which wires are Red/Positive and Black/Negative on these fans? - Electrical Engineering Stack Exchange

identification - Problem with molex connectors - Electrical Engineering Stack Exchange

What is the Use of a Decoupling Capacitor?

How to avoid noise/stray voltage in a cable which going to carry both AC and DC current? - Electrical Engineering Stack Exchange

Question - Which wire should I connect resistor to?