Chapter 3 - Section 3.1 - Functions - 3.1 Assess Your Understanding - Page 211: 56

The domain of h(x) is {${ x|x\ne2,x\ne-2}$}.

$h(x)=\frac{2x}{x^2-4}$ To find the domain of a rational function, we must set the denominator equal to 0 and solve for x. $x^2-4=0$ $x^2=4$ $x=\pm2$ This means that the domain is: {${ x|x\ne2,x\ne-2}$}