2026 NASS P1 Q1

The percentage Gross Domestic Product (GDP) growth of a country from 2014 to 2024 can be modelled by the quadratic equation \(\mathrm{G}(t)=0.7t^2-7t+11.2\), where \(t\) is the number of years after 2014.

1. By completing the square, find the year in which the percentage growth is the lowest, and state this minimum percentage GDP growth.[4]
2. Explain why this model may not be suitable for predicting the country’s percentage GDP growth in the long run.[1]