(1+Cos45°-Sin30°)(1-Sin45°+Cos60°)=

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 03:22:49
(1+Cos45°-Sin30°)(1-Sin45°+Cos60°)=

(1+Cos45°-Sin30°)(1-Sin45°+Cos60°)=
(1+Cos45°-Sin30°)(1-Sin45°+Cos60°)=

(1+Cos45°-Sin30°)(1-Sin45°+Cos60°)=
(1+Cos45°-Sin30°)(1-Sin45°+Cos60°)
=(1+√2/2-1/2)(1-√2/2+1/2)
=(1/2+√2/2)(3/2-√2/2)
=3/4+√2/2-1/2
=1/4+√2/2

很抱歉!算错了。

(1+2倍根号2)/2

原式=(1+√2/2 -1/2)(1-√2/2+ 1/2)
=1^2-(√2/2 -1/2)^2
=1-(1/2 -√2/2+1/4)
=1/4+√2/2

原式=[1+(Sin45°-Sin30°)][1-(Sin45°-Sin30°)]=1-(Sin45°-Sin30°)^2=1-1/2-1/4+2分之根号2=1/4+2分之根号2

Cos45°=Sin45°
Sin30°=Cos60°
(1+Cos45°-Sin30°)(1-Sin45°+Cos60°)
=(1+Cos45°-Sin30°)(1-Cos45°+Sin30°)
=1^1-(Cos45°-Sin30°)^2
1-[(√2/2)-(1/2)]^2
=1-[(3/4)-(√2/2)]
=(1/4)-(√2/2)
=(1-2√2)/4

解答如下:
=[1+(根号下2)/2 -1/2]*[1+(根号下2]/2+1/2]
=[1+(根号下2)/2]^2-1/4
=5/4-(根号下2)

4分之1加2倍根号2