What is it
Exponential growth and decay describe quantities that change by a constant percentage each time period (like compound interest or population growth), modelled by equations of the form y = a × bˣ.
Why it matters
Exponential change behaves very differently from linear change — understanding why it grows (or shrinks) so much faster is genuinely useful for understanding real financial and scientific contexts, not just exam questions.
Exam tip
Identify the growth or decay multiplier first (e.g. a 5% increase means multiplying by 1.05) before building the full equation — getting this single number right is the foundation of every exponential question.
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