Higher January 2023 Paper 1R Q20

20 Here is a sketch of the curve \(\;y = a\cos(x + b)°\;\) for \(\;0 \leqslant x \leqslant 360\)

Given that \(\;0 \lt b \lt 180\)

find the value of \(a\) and the value of \(b\)

(2)