救命啦！~！！急求！！在线等啊啊：已知f(x)=2x+3,g(2x-1)=f(x²-1)求g(x+1)的解析式

f(x)=2x+3

f(x²-1)=2(x²-1)+3=2x²+1
=0.5（4x²-4x+1）+2x-0.5+1
=0.5（2x-1）²+（2x-1）+1.5=g(2x-1)

g（x）=0.5x²+x+1.5

g(x+1)=0.5(x+1)²+(x+1)+1.5=0.5x²+2x+3

g(2x-1) = f(x²-1) = 2(x²-1) + 3 = 2x² + 1

设M = 2x - 1，则 x = （M + 1）/2

g（M）= 2[（M + 1）/2]² + 1 = （M + 1）²/2 + 1

所以 g(x) = (x + 1)²/2 + 1

那么

g(x+1) = [（x + 1) + 1]²/2 + 1

= (x + 2)²/2 + 1

g(x+1) = [（x + 1) + 1]²/2 + 1

= (x + 2)²/2 + 1