已知f(x+1)=x²-2x-15,则f(16)=?
问题描述:
已知f(x+1)=x²-2x-15,则f(16)=?
答
f(x+1)=x^2-2x-15
=x^2-2x+1-1-15
=(x-1)^2-16
=(x+1-2)^2-16
f(x)=(x-2)^2-16
f(16)=(16-2)^2-16
=14^2-16
=196-16
=180