當x→0時,1-cosx與axsinx是等價無窮小,則a=

當x→0時,1-cosx與axsinx是等價無窮小,則a=


1=lim(x→0)(1-cosx)/(axsinx)
=lim(x→0)(x^2/2)/(ax^2)=1/(2a)
所以:a=1/2