求极限:lim(1/x2-cot2x)x→0这么做错在哪:lim(sin2x-x2cos2x)/x2sin2x=lim(x2-x2(1-sin2x))/x4=lim(x2-x2+x4)/x4=1为什么不能这么求?lim(1/x^2-(cotx)^2) 其中x→0 =lim((sinx)^2-x^2(cosx)^2)/(x^2*(sinx)^2)=lim(x^2-x^2(1-(sinx^2))/
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![求极限:lim(1/x2-cot2x)x→0这么做错在哪:lim(sin2x-x2cos2x)/x2sin2x=lim(x2-x2(1-sin2x))/x4=lim(x2-x2+x4)/x4=1为什么不能这么求?lim(1/x^2-(cotx)^2) 其中x→0 =lim((sinx)^2-x^2(cosx)^2)/(x^2*(sinx)^2)=lim(x^2-x^2(1-(sinx^2))/](/uploads/image/z/638354-2-4.jpg?t=%E6%B1%82%E6%9E%81%E9%99%90%EF%BC%9Alim%EF%BC%881%2Fx2-cot2x%29x%E2%86%920%E8%BF%99%E4%B9%88%E5%81%9A%E9%94%99%E5%9C%A8%E5%93%AA%EF%BC%9Alim%28sin2x-x2cos2x%29%2Fx2sin2x%3Dlim%28x2-x2%281-sin2x%29%29%2Fx4%3Dlim%28x2-x2%2Bx4%29%2Fx4%3D1%E4%B8%BA%E4%BB%80%E4%B9%88%E4%B8%8D%E8%83%BD%E8%BF%99%E4%B9%88%E6%B1%82%3Flim%EF%BC%881%2Fx%5E2-%28cotx%29%5E2%29+%E5%85%B6%E4%B8%ADx%E2%86%920+%3Dlim%28%28sinx%29%5E2-x%5E2%28cosx%29%5E2%29%2F%EF%BC%88x%5E2%2A%28sinx%29%5E2%29%3Dlim%28x%5E2-x%5E2%281-%28sinx%5E2%29%29%2F)
求极限:lim(1/x2-cot2x)x→0这么做错在哪:lim(sin2x-x2cos2x)/x2sin2x=lim(x2-x2(1-sin2x))/x4=lim(x2-x2+x4)/x4=1为什么不能这么求?lim(1/x^2-(cotx)^2) 其中x→0 =lim((sinx)^2-x^2(cosx)^2)/(x^2*(sinx)^2)=lim(x^2-x^2(1-(sinx^2))/
求极限:lim(1/x2-cot2x)x→0
这么做错在哪:lim(sin2x-x2cos2x)/x2sin2x=lim(x2-x2(1-sin2x))/x4=lim(x2-x2+x4)/x4=1
为什么不能这么求?
lim(1/x^2-(cotx)^2) 其中x→0
=lim((sinx)^2-x^2(cosx)^2)/(x^2*(sinx)^2)
=lim(x^2-x^2(1-(sinx^2))/x^4
=lim(x^2-x2+x^4)/x^4
=1
用等价我穷小换算错在哪?
求极限:lim(1/x2-cot2x)x→0这么做错在哪:lim(sin2x-x2cos2x)/x2sin2x=lim(x2-x2(1-sin2x))/x4=lim(x2-x2+x4)/x4=1为什么不能这么求?lim(1/x^2-(cotx)^2) 其中x→0 =lim((sinx)^2-x^2(cosx)^2)/(x^2*(sinx)^2)=lim(x^2-x^2(1-(sinx^2))/
你的题目是怎样的?是1/(分母)还是 前后相减?
你写清楚点可以吗?
lim (1/x^2 - 1/xtanx)
= lim(xtanx - x^2)/(x^3 * tanx) 约去一个tanx
= lim (tanx - x)/x^3 上下都求导数(罗必达法则)
= lim (secx * secx -1)/3x^2
= lim (tanx * tanx)/3x^2
= 1/3与我的题目都...
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lim (1/x^2 - 1/xtanx)
= lim(xtanx - x^2)/(x^3 * tanx) 约去一个tanx
= lim (tanx - x)/x^3 上下都求导数(罗必达法则)
= lim (secx * secx -1)/3x^2
= lim (tanx * tanx)/3x^2
= 1/3
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