Grade 11 · Theory
Applications of exponents
Exponents and surds · about 3 min
Visual overview: Applications of exponentsExponential models describe populations, bacteria, radioactive decay and money.
Key points- Growth: A = A₀(1 + i)ⁿ. Decay: A = A₀(1 − i)ⁿ.
- Half-life problems ask for the time until half remains — set A = ½A₀.
- Interpret the numbers in context, with correct units.
- Sketching the model shows whether growth or decay is happening.
- Half-life — the time taken for a quantity to halve.
EXAM TIP
identify A₀ (the starting value) and i first; nearly every application question then reduces to substitution.