tan(X+45度)=1/3,(sinX-cosX)^2/cos2x?A.3B.-3C.2D.-2

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/24 08:29:17
tan(X+45度)=1/3,(sinX-cosX)^2/cos2x?A.3B.-3C.2D.-2
x)+Iӈ61}k=:řyqF@ڨQIOYEO&HX`@`d4LM/% e epe`q[$ } gT RX`6T ]C6 251=P<;Glw*ф 6GlHذD2AvO

tan(X+45度)=1/3,(sinX-cosX)^2/cos2x?A.3B.-3C.2D.-2
tan(X+45度)=1/3,(sinX-cosX)^2/cos2x?
A.3
B.-3
C.2
D.-2

tan(X+45度)=1/3,(sinX-cosX)^2/cos2x?A.3B.-3C.2D.-2
(sinx-cosx)^2/cos2x
=(sinx-cosx)/(cos^2x-sin^2x)
=(sinx-cosx)/(sinx+cosx)
=(tanx-1)/(1+tanx)
=tan(x-45°)=1/3

tan(x+45)=(tanx+1)/(1-tanx)=1/3
可得tanx