#lim_(x->oo) (sqrt(3x-5)+sqrt(2x+7))#?

1 Answer
Feb 28, 2018

#\lim _{x\to \infty }(\sqrt{3x-5}+\sqrt{2x+7})\ =\ infty#
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Explanation:

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#\lim _{x\to \infty }(\sqrt{3x-5}+\sqrt{2x+7})#

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According to the limit property, we have:

#\lim_{x\to a}[f(x)\pm g(x)]=\lim_{x\to a}f(x)\pm \lim _{x\to a}g(x)#

#=\lim_{x\to\infty\:}(\sqrt{3x-5})+\lim_{x\to\infty\:}(\sqrt{2x+7})#

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According to the limit property, we have:

#\lim_{x\toa}[f(x)]^b=[\lim_{x\toa}f(x)]^b#

#=\sqrt{\lim_{x\to\infty\:}(3x-5)}+\sqrt{\lim_{x\to\infty\:}(2x+7)}#

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#\text{Apply Infinity Property:}#

#\lim_{x\to\infty}(ax^n+\cdots+bx+c)=\infty ," " a>0\ \ \ ,\ \ \ \text{n is odd}#

#=\sqrt{\infty }+\sqrt{\infty }#

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#\text{Apply Infinity Property:} " "\infty ^c=\infty#

#=infty+infty#

#=infty#

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That's it!