Question

f（x）={4-x,x小于等于0 ｛f(x-1)-f(x-2),x大于0 则f(3)=

Answer 1

根据x>0 时,f(x)=f(x-1)-(x-2)有

f(2)=f(1)-f(0)

所以f(3)=f(2)-f(1)=[f(1)-f(0)]-f(1)=-f(0)

=-4