limit as x goes to infinity of: cos(1 / x) Solution represent cos(1/x) in series form : cos x = 1 - x2 /2! + x4 /4! .......... cos(1/x) = 1 - (1/2!)(1/x2 ) + (1/4!)(1/x4 ) ........... (1 - 1/2! (1/x2 ) + (1/4!)(1/x4 ).................) x this is form (-> 1)infinity e ( -1/2! 1/(x*x))x = e 0 = 1 answer !!!!.