(1)已知f(x+1)=根号下1-x²,求f(x) (2)已知f(x)={3x^2-5x+2(x>1),3x-1(x

(1)已知f(x+1)=根号下1-x²,求f(x) (2)已知f(x)={3x^2-5x+2(x>1),3x-1(x
(1)已知f(x+1)=根号下1-x²,求f(x) (2)已知f(x)={3x^2-5x+2(x>1),3x-1(x

(1)已知f(x+1)=根号下1-x²,求f(x) (2)已知f(x)={3x^2-5x+2(x>1),3x-1(x
1.令x+1=t 即x=t-1
f(t) = f(x+1)=√(1-x²)=√( 1+x)(1-x)=√t(2-t)
所以f(x)=√x(2-x)
2.令x=t+1
当x>1,即t+1>1,t>0时
f(t+1)=f(x)=3(t+1)²-5(t+1)+2=3t²+t
当x