lim(x趋于0)((x^2.sin(1/x))/sinx)为什么不能用等价无穷小替换sin(1/x)和sinx?

求极限,lim x趋于0 x * sin 1/x lim(1+sinx-sin(sinx))^x^-3 x趋于0 lim x趋于0 （x-sin x）/x^3 lim[1+sin(xy)]^(y/x)x趋于0 y趋于π,求极限 求极限lim[sin(x^3)/x(x-ln(1+sinx))] x趋于0lim[sin(x^3)/x(x-ln(1+sinx))] x趋于0 lim x^sin x （x趋于0-） lim:x平方-1/sin(x-1),x趋于1 求极限lim(x趋于0时)sin(sinx)/x 求极限:lim(x趋于0)(e^sin^3x-1)/x(1-cosx), x趋于0时求lim(sin/x)^(1/[1-cosx])是sinx/x lim (sin(x+△x)-sin x)/△x x趋于0 lim(x趋于0)(x^2-sin^2xcos^2x)/((x^2)sin^2x) lim(根号下(1+sin^2x)-1)/xtanx x趋于0 lim(x趋于0)((x^2.sin(1/x))/sinx)为什么不能用等价无穷小替换sin(1/x)和sinx? 求 lim(tan x-sin x)/(sin x)^3 x趋于0的极限值详细步骤 lim (x^x-sin(x)^x)/(sin(x)sin(x)ln(1+tan(x))) x趋于零 当x趋于0时:lim (tan x - sin x )/x^3 lim [(a^x+b^x+c^x)/3]^(1/x) ( a,b,c > 0 ) 请老师回答问题,lim（n趋于无穷大）(1^n+2^n+3^n)1/n次方=?lim(x趋于无穷大）sin2x/x=?lim(x趋于0）sin(sinx)/x=?