The following diagram shows the curve \(y = a \sin(b(x + c)) + d\), where \(a, b, c\) and \(d\) are all positive constants and \(x\) is measured in radians. The curve has a maximum point at \((1, 3.5)\) and a minimum point at \((2, 0.5)\).
\includegraphics{figure_4}
- Write down the value of \(a\) and the value of \(d\). [2]
- Find the value of \(b\). [2]
- Find the smallest possible value of \(c\), given that \(c > 0\). [2]