A limit problem I created

lookagain

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Evaluate:\displaystyle Evaluate:


limx(x6+x56 + x3+x23 + x2+x  3x)\displaystyle \lim_{x \to \infty}\bigg(\sqrt[6]{x^6 + x^5} \ + \ \sqrt[3]{x^3 + x^2} \ + \ \sqrt{x^2 + x} \ - \ 3x\bigg)
 
lookagain said:
Evaluate:\displaystyle Evaluate:


limx(x6+x56 + x3+x23 + x2+x  3x)\displaystyle \lim_{x \to \infty}\bigg(\sqrt[6]{x^6 + x^5} \ + \ \sqrt[3]{x^3 + x^2} \ + \ \sqrt{x^2 + x} \ - \ 3x\bigg)

limx(x6+x56 + x3+x23 + x2+x  3x)\displaystyle \lim_{x \to \infty}\bigg(\sqrt[6]{x^6 + x^5} \ + \ \sqrt[3]{x^3 + x^2} \ + \ \sqrt{x^2 + x} \ - \ 3x\bigg)

= limx(x1+1x6 + x1+1x3 + x1+1x  3x)\displaystyle = \ \lim_{x \to \infty}\bigg(x\sqrt[6]{1 + \frac{1}{x} } \ + \ x\sqrt[3]{1 + \frac{1}{x}} \ + \ x\sqrt{1 + \frac{1}{x}} \ - \ 3x\bigg)

= limx(x(1+16x....) + x(1+13x...) + x(1+12x...)  3x)\displaystyle = \ \lim_{x \to \infty}\bigg(x(1 + \frac{1}{6x}....) \ + \ x(1 + \frac{1}{3x}...) \ + \ x(1 + \frac{1}{2x}...) \ - \ 3x\bigg)

= limx(16.... + 13... + 12... ) = 1\displaystyle = \ \lim_{x \to \infty}\bigg( \frac{1}{6}.... \ + \ \frac{1}{3}... \ + \ \frac{1}{2}... \ \bigg) \ = \ 1
 
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