直接带入x=1
=lim(1-2+4)/2=3/2
上下分子分母乘以(√(x-2)+√2)
=lim((√(x-2)+√2)(x-4)/[(√(x-2)-√2)(√(x-2)+√2)]
=lim((√(x-2)+√2)(x-4)/(x-4)
=lim((√(x-2)+√2)
=2√2
=lim2(sinx)^2/(xsinx)
=lim2(sinx)^2/(sinx*sinx) sinx~x 当x→0
=2
=lim(1-x)^(-1/x)*(-1)
=lim[(1-x)^(-1/x)]^(-1)
=e^(-1)
=lim[sinx(1/cosx-1)]/x^3
=lim[(1/cosx-1)]/x^2 sinx~x 当x→0
=lim[(1/cosx*(1-cosx)]/x^2
=lim[(1/cosx*2(sinx/2)^2]/x^2
=lim[(1/cosx*2(x/2)^2]/x^2
=lim[(1/cosx*1/2)
=1/2
能不能分开,哪题是哪题大神?