2.1.43 Calculation of Limits

Condition: calculate the limits of sequences (if they exist) using the corresponding properties. If the limits do not exist, justify the answer. a) \ (\ lim _ {n \ rightarrow \ infty} \ sin \ left (\ frac {\ pi} {2} \ right) \), b) \ (\ lim _ {n \ rishtarroul} \ frac {-9 n^{5} +7 n^{3} -3} {17 n^{8} -4 n+10} \) c) \ (\ lim _ {n \ rightarrow \ infty} \ frac {2} {\ cos \ left (\ frac {\ pi n-2} {2 n} \ right)} \), D) \ (\ LIM _ {N \ RIGHTARROW \ InFty} \ FRAC {-2 n^{3} -17 n^{2} +13 N} {3} -34 N^{2} +9 IUS} +9} +9} +9} +9} +9} +9} \).