limx→0sin3x/sin5x,求极限

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limx→0sin3x/sin5x,求极限

limx→0sin3x/sin5x,求极限
limx→0sin3x/sin5x,求极限

limx→0sin3x/sin5x,求极限
lim sin3x/sin5x
=lim 3x/(5x)
=3/5
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当x趋于0时,sin3x等价于3x,sin5x等价于5x

sin3x/3x=1 sin5x/5x=1 自己带进去算 极限是3/5

用罗比达法则
lim(x→0) sin3x/sin5x
=lim(x→0) (cos3x*3)/(cos5x*5)
=(1*3)/(1*5)
=3/5