Question

初二数学二次根式

Answer 1

原式=√[(b^nc^(n+1)/a^n)^2*a]
=(b^nc^(n+1)*√a/a^n

Answer 2

-3<=x<=2
-2<=-x<=3
2^(-2)<=2^(-x)<=2^3

令a=2^(-x)
则1/4<=a<=8
y=f(x)=a²-a+12
=(a-1/2)²+47/4
1/4<=a<=8
所以a=1/2，最小值=47/4