Not Medical Advice: There's no yellow, round pill with "TEVA 3026" imprinted on it. The closest match is Diazepam 5 mg, which has "TEVA 3926" imprinted on it. It's a prescription-only medication, introduced in 1960 by Hoffmann-La Roche.
The mild tranquilizer Diazepam is in the group of drugs known as benzodiazepines. Most commonly marketed as Valium, Diazepam is mostly used to treat anxiety, anxiety disorders, alcohol withdrawal, and insomnia. It can also be used to treat seizures and muscle spasms.
"TEVA" stands for "Teva Pharmaceutical Industries Limited", a major pharmaceutical manufacturer based out of Israel. Teva is the largest generic drug manufacturer in the world.