[填空题]
The average daily hou 0fax-z dea +zevnoq9255 j4yqm:nphso mcpjf/9 ikoa;ro :4h a;+12y rs of sunlight, S, during a 12-month period in a particular town is given by the r :kf;h;ajpooimm2y/n19 :c4psha +ofunction
S(t)=acos(bt−π)+d,where time, t, is measured in months, a and d are constants, and b is measured in degrees.
The graph of S versus t is shown in the diagram below.
1.Find the value of
(1)a;
(2)d.
2.Find the value of b. $^{\circ}$
3.Write down the values of t when the average daily sunlight is 10 hours.
t =
