Zadanie 7a, Paper 1, maj 2024, TZ2, Matematyka AA IB SL

A growth chamber repeats a lighting cycle. In chamber A the light intensity is $f(t)=a\sin(bt)+c$ for 0≤t≤12, with a,b,c>0 and angles in radians. The graph shows exactly one complete cycle. A monitoring procedure requires intensity at least 20 units. Chamber B uses $g(t)=4\sin(\pi t/6)+15$ over the same interval. The supplied graph for chamber A applies to every part.