数列求和 sin²1°+sin²2°+sin²3°+.+sin²88°+sin²_数学解答

数列求和 sin²1°+sin²2°+sin²3°+.+sin²88°+sin²89°
数列求和sin²1°+sin²2°+sin²3°+.+sin²88°+sin²89°
求详细解答过程!

人气：217 ℃　时间：2020-04-08 13:58:26

解答

sin(π/2-x)=cosx
原式=sin^2 1°+……+sin^2 44°+1/2+cos^2 44°+……+cos^2 1°
=44+1/2
=89/2