lim(x+5)(2x-1)/(x^2-3x-1)球极限,x无穷大

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lim(x+5)(2x-1)/(x^2-3x-1)球极限,x无穷大

lim(x+5)(2x-1)/(x^2-3x-1)球极限,x无穷大
lim(x+5)(2x-1)/(x^2-3x-1)球极限,x无穷大

lim(x+5)(2x-1)/(x^2-3x-1)球极限,x无穷大
无穷大,只比贵高次幂
=lim2x^2/x^2=2

lim(x+5)(2x-1)/(x^2-3x-1)=lim(1+5/x)(2-1/x)/(1-3/x-1/x^2),当x趋于无穷大时,lim(1+5/x)=1,lim(2-1/x)=2,lim(1-3/x-1/x^2)=1,故所求极限为2.

lim(x+5)(2x-1)/(x^2-3x-1)
=lim(2x^2+9x-5)/(x^2-3x-1)=2

=lim(x+5)(2x-1)/(x^2-3x-1)
=lim(2x^2+9x-5)/(x^2-3x-1)
=lim2x^2/x^2
=2

lim(x+5)(2x-1)/(x^2-3x-1)
=lim(2x²﹣x+10x﹣5)/(x²﹣3x﹣1)
=lim(2x²+9x﹣5)/(x²﹣3x﹣1)
因为分子分母最高次幂都是2 ,所以极限等于他们的系数之比
=2∕1=2