I read that the Electric Guitar was invented in 1936
When was it first used on a sound recording?
2) When did the Electric Bass guitar come into use and 1st recording date for this please

Electric guitar- Yep. And Rickenbacker, National, and Gibson were the first companies to market the product. They "were essentially acoustic instruments with pickups for an amplifier, and like other electric instruments they gained their first popularity in the country and rhythm-and-blues fields, where nightclub and tavern venues were the rule and added volume was required. The first solid-body electric guitar, with entirely electronic amplification, was built for country guitarist Merle Travis around 1946; shortly after that, the Fender company's Broadcaster model, soon renamed the Telecaster, set the pattern for numerous instruments that followed..."
- Allmusic

Electric bass- "Jazz upright players were the first to make the switch, from upright to electric bass." 1926 saw the "first 'Electric Upright' from Lloyd Loar" (although the last link tells of the disputed date of 1924).
- History of The Electric Bass
- History of the Bass Guitar
- Evolution