Question

求极限,最好写在纸上,拍下来因为还没有学罗比达法则,只能用无穷小量,提示第一问答案是2/π,第二问答案是/13,

Answer 1

1,极限=lim(1-x)(sinπx/2)/(cosπx/2)=lim(1-x)/(cosπx/2),用洛必达,=lim(-1)/(-π/2)(sinπx/2)=2/π

2,极限=lim(sin3x)(cosx)/(cos3x)(sinx)=limsin3x/sinx=-1