若函数f(x)满足3f(x)+2f(-1/x)=4x,求f(x)

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/04 03:19:27
若函数f(x)满足3f(x)+2f(-1/x)=4x,求f(x)若函数f(x)满足3f(x)+2f(-1/x)=4x,求f(x)若函数f(x)满足3f(x)+2f(-1/x)=4x,求f(x)3f(x

若函数f(x)满足3f(x)+2f(-1/x)=4x,求f(x)
若函数f(x)满足3f(x)+2f(-1/x)=4x,求f(x)

若函数f(x)满足3f(x)+2f(-1/x)=4x,求f(x)
3f(x)+2f(-1/x)=4x ①
用-1/x取代x,那么3f(-1/x)+2f(x)=-4/x ②
①×3-②×2,得:5f(x)=12x+8/x
所以f(x)=12/5*x+8/(5x)

3f(x)+2f(1/x)=4x --------1
把1/x代入上式,得到
3f(1/x)+2f(x)=4/x--------2
1式*3-2式*2
解方程,得到
f(x)=(12x-8/x)/5


令x=-1/x
则有3f(-1/x)+2f(x)=4*(-1/x)
结合3f(x)+2f(-1/x)=4x
解得
f(x)=(4/5)*(3x+2/x)