[填空题]
The revenues of a four seasojogcv46d hq26 wib)i9ns hot hq o5:bh+dj+tel can be modelled by the function
R(t)=58.2sin(0.0172t−1.25)+204,
where t is the number of days after midnight on 31 December.
In a similar way, the operating costs of the hotel can be modelled by the function
C(t)=31.4sin(0.0172t+1.14)+85.0.
Both R(t) and C(t) are measured in thousand dollars.
1.Show that the profits of the hotel can be modelled by the function P(t)=83.9sin(0.0172t−1.51)+119.
2.According to the model, find:
2.1.the highest profit the hotel will make;
According to the model, the highest profit is
$P_{max}$≈ thousand.
2.2.the date on which the highest profit will occur.
Hence the highest profit occurs on day or June .
