人教版高中数学课本题:三角函数~复习参考题5
2022-12-12 本文已影响0人
易水樵
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27.在地球公转过程中,太阳直射点的纬度随时间周而复始不断变化.
(1)如图,设地球表面某地正午太阳高度角为 ,
为此时太阳直射点的纬度,
为当地的纬度值,那么这三个量满足
.
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某科技小组以某年春分(太阳直射赤道且随后太阳直射点逐渐北移的时间)为初始时间,统计了连续 天太阳直射点的纬度平均值 (太阳直射北半球时取正值,太阳直射南半球时取负值).下面是该科技小组的三处观测站成员在春分后第
天测得的当地太阳高度角数据:
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请根据数据完成上面的表格(计算结果精确到 );
(2)设第 天时太阳直射点的纬度平均值为
. 该科技小组通过对数据的整理和分析,推断
与
近似满足函数
,其中
为北回归线的纬度值,约为
,试利用(1)中的数据,估计
的值(精确到
).
(3)定义从某年春分到次年春分所经历的时间为一个回归年,求一个回归年对应的天数(精确到 );
(4)利用(3)的结果,估计每 年中,应设定多少个年,可使这
年与
个回归年所含的天数最为接近(精确到
).