# Which of the following pairs of functions are equal ?

(A) $f(x)=\large\frac{x}{|x|}$ $and\:\:g(x)=1$ (B) $f(x)=\sqrt {x^2}\:\:and\:\:g(x)=|x|$ (C) $f(x)=\large\frac{|x|}{x^2}$ $and\:\:g(x)=\frac{1}{x}$ (D) $f(x)=\sqrt {x^2}\:\:and\:\:g(x)=x$

Toolbox:
• $|x|=x,$ if $x\geq 0$ and $|x|=-x$ if $x<0$
$\sqrt{x^2}=\pm x=|x|$