来自戴惠芬的问题
sin2(π/11)+sin2(9π/22)
sin2(π/11)+sin2(9π/22)
1回答
2020-07-27 06:46
sin2(π/11)+sin2(9π/22)
sin2(π/11)+sin2(9π/22)
sin²(π/11)+sin²(9π/22)
=sin²(π/11)+sin²[(π/2)-(π/11)]
=sin²(π/11)+cos²(π/11)
=1