sin75=?怎么算最方便

来源:百度知道 编辑:UC知道 时间:2024/06/06 03:02:00

sin75
=sin(45+30)
=sin45cos30+cos45sin30
=(√2/2)(1/2)+(√2/2)(√3/2)
=(√6+√2)/4

sin75°
=sin(30°+45°)
=sin30°cos45°+cos30°sin45°
=(1/2)*(√2/2)+(√3/2)*(√2/2)
=(√2+√6)/4.

一般的,sin(α±β)=sinαcosβ±cosαsinβ.

“√”是根号的意思。

sin75
=sin(45+30)
=sin45cos30+cos45sin30
=(√2/2)(1/2)+(√2/2)(√3/2)
=(√6+√2)/4

sin75°
=sin(45°+30°)
=sin45°cos30°+cos45°sin30°
=(√2/2)*(√3/2)+(√2/2)*(1/2)
=√6/4+√2/4
=(√2+√6)/4

sin75=sin(30°+45°)
=sin30°cos45°+cos30°sin45°
=(1/2)*(√2/2)+(√3/2)*(√2/2)
=(√2+√6)/4.

sin(a+b)=sinacosb+cosasinb
sin75=sin(30+45)=sin30cos45+cos30sin45
==(√2/2)(1/2)+(√2/2)(√3/2)
=(√6+√2)/4