Proportion and graphs (AQA GCSE Maths): Flashcards

'is proportional to'

Quantities increase/decrease together at same rate

$y = kx$ where $k$ is constant

Straight line through origin (0,0)

One increases while other decreases, product constant

$y = \frac{k}{x}$ where $k$ is constant

Curved line (reciprocal graph)

$y \propto x$

$y \propto \frac{1}{x}$

Opposite directions