AP Calculus ABhardmcq1 pt

limx(x2+2xx)=\lim_{x\to\infty}\left(\sqrt{x^2+2x}-x\right)=

A.00
B.11
C.22
D.\infty

Explanation

Core Concept

Rationalize: x2+2xx=(x2+2x)x2x2+2x+x=2xx2+2x+x\sqrt{x^2+2x}-x=\frac{(x^2+2x)-x^2}{\sqrt{x^2+2x}+x}=\frac{2x}{\sqrt{x^2+2x}+x}. Dividing numerator and denominator by xx gives 21+2/x+122=1\frac{2}{\sqrt{1+2/x}+1}\to\frac{2}{2}=1.

Correct Answer

B11

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