To find \(c\), we use the fact that the graph crosses the \(x\)-axis at \(C(\cos^{-1} c, 0)\). At this point, \(y = 0\), so:

\(a \, \cos(\cos^{-1} c) - b = 0\)

\(a \, c - b = 0\)

\(c = \frac{b}{a}\)

To find \(d\), we use the fact that the graph crosses the \(y\)-axis at \(D(0, d)\). At this point, \(x = 0\), so:

\(y = a \, \cos(0) - b\)

\(y = a \, (1) - b\)

\(d = a - b\)