a) \( \lim{ \left( \sqrt{n^4-3n^2+5}-\sqrt{n^3+2n} \right) } = ? \)
b) \( \lim{ \left( \sqrt{n^4-3n^2+5}-\sqrt{n^4+2n} \right) } = ? \)
c) \( \lim{ \left( \sqrt{n^4-5n^2+4}+n^2 \right) } = ? \)
d) \( \lim{ \left( \sqrt{n^4-5n^2+4}-n^2 \right) } = ? \)
e) \( \lim{ \left( \sqrt{n^4-n}-\sqrt{n^2+1} \right) } = ? \)