Sometimes you do use that stuff. If you're working on electrical/control systems engineering or anything close to that... you might. My first job that I got during college was calibrating pressure tanks that needed to have control systems able to handle pressure differences and hickups that needed to be programmed into micro controllers inside MCC units. That uses transformation/transfer functions to get the proper function to handle those differences, which are part of differential equations (which is the step equal or after Calc 3).
You'd be surprised how many "seasoned" engineers I have met in my life so far who don't have a single clue of what they actually do, some are past middle age.


