x=(2^m) +12^m=x-1y=3+4^m=3+(2^m)²=3+(x-1)²=x²-2x+4所以：y=x²-2x+4
x-1=2^mm=log2(x-1)y=3+4^log2(x-1)y=3+2^(2log2(x-1))y=3+(x-1)^2
y=2x+1
