Question

limx->0 f(ax)/x=A 求limx->0 x/f(bx)=?

Answer 1

要求a,b都不为0才能解

令ax=t 则 有 limt->0 af(t)/t = A, limt->0 f(t)/t = A/a

再令bx=u

所以 limx->0 x/f(bx) = imx->0 u/(bf(u)) =1/b * 1/( f(u)/u )

=1/b * 1/(A/a) =a/(bA)