只要满足0/0型后者∞/∞型,反复运用L'Hospital法则,分子分母同时求导就可以了.
原式=lim {cos[sin(sinx)]*cos(sinx)*cosx}/sec²x
=lim {cos[sin(sinx)]*cos(sinx)*cos³x}
=lim {cos[sin(sinx)] * lim cos(sinx) * lim cos³x
=1*1*1
=1
只要满足0/0型后者∞/∞型,反复运用L'Hospital法则,分子分母同时求导就可以了.
原式=lim {cos[sin(sinx)]*cos(sinx)*cosx}/sec²x
=lim {cos[sin(sinx)]*cos(sinx)*cos³x}
=lim {cos[sin(sinx)] * lim cos(sinx) * lim cos³x
=1*1*1
=1