Answer:
h(t) = 1.75 cos (π/6) + 2.25
Explanation:
the amplitude of a regular cos graph is 1 (it alternates between +1 and -1 on the y-axis). that is, amplitude = (1 - -1)/2 = 2/2 = 1.
this graph has amplitude (4 - 0.5)/2 = 3.5/2 = 1.75.
the graph repeats for every sixth value on the x-axis (time axis).
in the x-axis direction, a cos graph that becomes 6 times larger is cos (π/6). a cos graph that becomes 6 times smaller is cos (6π).
so for our graph, it is cos (π/6).
what about the y-shift?
the graph has already been enlarged 1.75 times parallel to the y-axis.
it crosses the y-axis at 4. so the y-shift is 4 - 1.75 = 2.25.
so our graph is given by h(t) = 1.75 cos (π/6) + 2.25