It is given that \(y=\dfrac{\ln(2x^2+1)}{x+2}\), \(x\ne-2\).
Find \(\dfrac{\mathrm{d}y}{\mathrm{d}x}\).[3]
Given that \(x\) increases from \(1\) to \(1+h\), where \(h\) is small, find the approximate corresponding change in \(y\).[2]
When \(x=1\), the rate of change in \(y\) is \(3\) units per second. Find the corresponding rate of change in \(x\).[2]