[填空题]
The average daily hour nwbp blp h0n +59)7;ogl4b. 3ltxxzhss of sunlight, S, during a 12-month period inmli /:, sgrgqbh5563jrwkga7 a particular town 5s76jwr5:hlq gi g bg/,r3makis given by the function
$S(t)=\,acos(bt−π)+d$,
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.b = $^{\circ}C$
3.Write down the values of t when the average daily sunlight is 10 hours.
