The line y=0y=0 is a horizontal asymptote of the rational function f(x)=(17x)/(2x^2+3)f(x)=17x2x2+3 since the degree of the bottom (denominator) is greater than the degree of the top (numerator). Furthermore, the denominator 2x^2+32x2+3 has no real roots (the roots are the imaginary numbers pm i sqrt{3/2}±i√32). Hence, the function has no vertical asymptotes.
To confirm the horizontal asymptote, you can do the following limit calculation, which I'm not rigorously justifying:
lim_{x-> pm infty}(17x)/(2x^2+3)=lim_{x-> pm infty}(17x)/(2x^2+3) * (1/x^2)/(1/x^2)
=lim_{x-> pm infty}(17/x)/(2+3/x^2)=(lim_{x->pm infty}(17/x))/(lim_{x->pm infty} 2+lim_{x->pm infty}(3/x^2))=0/(2+0)=0