计算：sin²1°+sin²2°+sin²3°...+sin²45°+sin&#

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/11 13:09:08

计算：sin²1°+sin²2°+sin²3°...+sin²45°+sin²46°...+sin²89°

sin²1°+sin²2°+sin²3°...+sin²45°+sin²46°...+sin²89°
＝sin^2(90-89)+sin^2(90-88)+...sin^2(90-46)+...+sin²45°+sin²46°...+sin²89°
=(cos89)^2+(cos88)^2+.+sin²45°+sin²46°...+sin²89°
=44+1/2
＝44.5

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