[1-X^(1/2)]/[1-X^(1/3)]当X→1时的极限

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[1-X^(1/2)]/[1-X^(1/3)]当X→1时的极限
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[1-X^(1/2)]/[1-X^(1/3)]当X→1时的极限
[1-X^(1/2)]/[1-X^(1/3)]当X→1时的极限

[1-X^(1/2)]/[1-X^(1/3)]当X→1时的极限
因为x->1时分子分母都是0,用洛必塔法则,即对分子分母分别求导
limx->1[1-X^(1/2)]/[1-X^(1/3)]
=limx->1[1/2*x^(-1/2)]/[1/3*x^(-2/3)]
=1/2 / 1/3
=3/2

换元t=x^(1/6),则原式=lim(t→1) (1-t^3)/(1-t^2)=lim(t→1) (1+t+t^2)/(1+t)=3/2