cos2(cos(cos(t))) is a periodic function with period π (180°).
Its amplitude is:
½(cos2(cos(cos(π)))-cos2(cos(cos(π/2))))=½(0.735398-0.291927)=0.221736 (approx).
Here's a table of values showing maxima at t=0, π, and minimum at t=½π. The function is symmetrical about t=0, and you can see the symmetry in the interval [0,π], on either side of t=½π.
t |
cos2(cos(cos(t))) |
0 |
0.735398 |
0.1π (18°) |
0.698915 |
0.2π (36°) |
0.594614 |
0.3π (54°) |
0.453296 |
0.4π (72°) |
0.335865 |
½π (90°) |
0.291927 |
0.6π (108°) |
0.335865 |
0.7π (126°) |
0.453296 |
0.8π (144°) |
0.594614 |
0.9π (162°) |
0.698915 |
π (180°) |
0.735398 |