Direct and Indirect Proportion (Grade 12 NSC Matric Mathematical Literacy): Flashcards

Both quantities change by the same factor in the same way

Straight line passing through origin (0,0)

$y = kx$ where $k$ is constant

One quantity increases as the other decreases

Product of two quantities always stays the same

$x \times y = k$ where $k$ is constant

Rectangular hyperbola

Curve never touches either axis

Quantities cannot equal zero in most real-world scenarios

Direct: straight line; Indirect: smooth curve