设f(x)=ax^5+bx^3+cx-5(a、b、c是常数),且f(-7)=7,则,f(7)=
问题描述:
设f(x)=ax^5+bx^3+cx-5(a、b、c是常数),且f(-7)=7,则,f(7)=
答
f(-7)=7
即-a7^5-b7^3-c7-5=7
a7^5+b7^3+c7-5=f(7)
两式相加得
-10=7+f(7)
∴f(7)=-17