2025 IGCSE Additional Mathematics October/November 0606/22 Q4

Variables \(x\) and \(y\) are such that when \(\mathrm e^y\) is plotted against \(x^3\), a straight-line graph is obtained.

This line passes through the points (1,13.5) and (7.5,0.5).

1. Find \(y\) in terms of \(x\).[4]
2. Find the values of \(x\) for which your equation is valid.[2]