Question

函数f(x)=ax³+bx+c,若f(3)=1,则f(-3)=

Answer 1

f(3)=3³a+3b+c=27a+3b+c

f(-3)=(-3)³a+(-3)b+c=-27a-3b+c

∴f(3)+f(-3)=0+0+2c=2c

而f(3)=1,∴f(-3)=2c-1