求极限lim(x→π/4) 1+sin2x/1-cos4x

来源:学生作业帮助网 编辑:六六作业网 时间:2024/07/08 12:09:37
求极限lim(x→π/4)1+sin2x/1-cos4x求极限lim(x→π/4)1+sin2x/1-cos4x求极限lim(x→π/4)1+sin2x/1-cos4xx→π/4时,直接代入,得sin

求极限lim(x→π/4) 1+sin2x/1-cos4x
求极限lim(x→π/4) 1+sin2x/1-cos4x

求极限lim(x→π/4) 1+sin2x/1-cos4x
x→π/4时,直接代入,得
sin2x→1,cos4x→-1
则极限为1
我想题目可能是
lim(x趋于派/4) 1-sin2x/1+cos4x
=lim 1-cos(π/2-2x)/1-cos(π-4x)
=lim (1/2)(π/2-2x)² / (1/2)(π-4x)²
=lim (1/4)(π-4x)² / (π-4x)²
=1/4