I use algebra and trigonometry all the time in my daily life. When I prepare meals, watch TV, go out on a date, even during sex. I’ll create sample equations with X and Y. I might create one equation predicting the chances that X and Y will have oral sex that night and that Y won’t hate X the next day.
There are obvious patterns to human interaction, so I’ll test equations to see what will work out and what won’t. If there’s more than two people involved, triangles often come in handy, otherwise you might find yourself in bed wrestling three unknowns.