若函数f(x+1)=x²-2x,求f(3)的值,及f(x)
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若函数f(x+1)=x²-2x,求f(3)的值,及f(x)
若函数f(x+1)=x²-2x,求f(3)的值,及f(x)
若函数f(x+1)=x²-2x,求f(3)的值,及f(x)
f(3) = f(2+1) = 2^2-2×2 = 4-4 = 0 此时f(x+1)中的x=2
f(x) = f(x-1+1) =(x-1)^2-2(x-1)= x^2-2x+1-2x+2= x^2-4x+3 此时f(x+1)中的x=(x-1)
f(3)=2*2-4=0
F(X)=(x-1)^2-2(x-1)=x^2-4x+3