Tan(A+45度)+Tan(A-45度)=2Tan2A

来源:学生作业帮助网 编辑:六六作业网 时间:2024/05/15 05:19:01
Tan(A+45度)+Tan(A-45度)=2Tan2ATan(A+45度)+Tan(A-45度)=2Tan2ATan(A+45度)+Tan(A-45度)=2Tan2ATan(A+45)+Tan(A-

Tan(A+45度)+Tan(A-45度)=2Tan2A
Tan(A+45度)+Tan(A-45度)=2Tan2A

Tan(A+45度)+Tan(A-45度)=2Tan2A
Tan(A+45)+Tan(A-45)
=(tanA+1)/(1-tanA)+(tanA-1)/(1+tanA)
=(tanA+1)^2/(1-tan^2A)+(tanA-1)^2/(tan^2A-1)
=[(tanA+1)^2-(tanA-1)^2]/(1-tan^2A)
=4tanA/(1-tan^2A)
=2tan2A

tan(A+45度)=[tanA+tan(45度)]/[1-tanA*tan(45度)]
再根据公式化简就OK了