Exponential law and an additional line

The variables \(x\) and \(y\) are related by \(y=Ae^{kx}\), where \(A\) and \(k\) are constants. The graph of \(\ln y\) against \(x\) is a straight line passing through \((0,\,1.2)\) and \((2,\,0.4)\).

1. Find the value of \(A\), correct to 3 significant figures, and the value of \(k\).[3]
2. Find the value of \(x\) for which \(y=1\).[2]
3. State the equation of the straight line that should be drawn on the same graph to solve \(Ae^{kx}=2e^{0.1x}\), and hence find the exact solution.[3]