数学问题：用洛必达法则求极限。第4题。求教 用洛必达法则求函数的极限第4题
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图
如图所示
lim(x->π) sin3x/tan5x (0/0)
lim(x->π) 3cos3x/[5(sec5x)^2]
=-3/5
(4)
lim (sin3x/tan5x)
x→π
=lim 3cos3x/(5sec²5x)
x→π
=3·cos3π/(5sec²5π)
=3·(-1)/[5·(-1)²]
=-3/5
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