2.1.82 Calculation of Limits

Condition: calculate the limits: a) \ (\ lim _ {x \ rightarrow \ infty} \ frac {3 x^{4}+x^{2} -6} {2 x} -x-2} \), b) \ ({x \ rihtarway 0} \ frac {x} {\ sqrt {1+3 x-1}} \) c) \ \ (\ lim _ {x \ rightarrow 0} \ frac {5 x} {\ arctan x} \), d) \ (\ lim {x \ riertarren 0} (1+2 x)^{1 / x} \).