已知f(x)=ax3+b/x+3,且f(5)=5,则f(-5)是多少
问题描述：
已知f(x)=ax3+b/x+3,且f(5)=5,则f(-5)是多少
答
因为
f（x）=ax^3+b/x+3
f(5)=a(5)^3+b/5+3=5
a(5)^3+b/5=2
a(-5)^3+b/(-5)=-2
f(-5)=a(-5)^3+b/(-5)+3
=-2+3
=1