Cotangent
Given the arithmetic sequence 11, 7, 3,... Find the 301^{st} term, a_{301} a_{n}= a_{1}+ (n-1) d a_{301}= 11+ (300-1)·(-4)=-1189
Compute the 21 (th) term of the arithmetic sequence where a_{5} = -14 and a_{7} = -22
Solution =