lim2^3n-3^(2n+1)/2^3n+3^2n趋近无穷大等于多少

问题描述:

lim2^3n-3^(2n+1)/2^3n+3^2n趋近无穷大等于多少

原式=lim(2^1.5)^2n-3×3^2n/(2^1.5)^2n+3^2n=lim[(2^1.5)/3]^2n-3/[(2^1.5)/3]^2n+1=-3