What Is a Control Variable? Definition and Examples

Explainer Zone™ on Instagram: "This video shows a vintage pen plotter, a type of early computer-controlled drawing machine widely used from the 1970s to early 1990s for technical drafting, engineering diagrams, maps, and typography. Unlike modern printers that spray ink, a pen plotter physically moves an actual pen across the paper using precision motors and coordinate commands. These machines were known for producing extremely accurate straight lines and curves, which made them essential for ar