lim x→0 tan x/x=

lim x→0 tan x/x=




lim(x→0)tan(x)^2/sin3x
求極限,先謝


General solution:
lim(x→0)tan²;x/sin3x
=lim(x→0)sin²;x/cos²;x*1/sin3x
=lim(x→0)sin²;x/x²;*x²;/cos²;x*3x/sin3x*1/3x
=lim(x→0)(sinx/x)²;*(3x/sin3x)*(x/3)
=1²;*1*0/3
=0



〔x趨近於0〕lim x/ ln(1+x)=1等式對麼


lim(1/ln(1+x)-1/x)
=lim[x-ln(1+x)]/xln(1+x)
=lim[1-1/(1-x)]/[ln(1+x)+x/(1+x)]
=limx/[x+(1+x)ln(1+x)]
=lim1/[ln(1+x)+1+1]=1/2