78.quad lim_(x rarr4)[(1)/(ln^(2))sec^(2)(1)/(m^(2))+(2)/(sin^(2))sec^(2)(4)/(n^(2))+...+(n)/(n^(2))sec^(2)1]" equals to "

Evaluate: lim_(n rarr oo)[(1)/(n^(2))sec^(2)(1)/(n^(2))+2/n^(2)sec^(2)(4)/(n^(2))+...+(1)/(n)sec^(2)1]]

{:(" "Lt),(n rarr oo):} [ (1)/(n^(2)) sec^(2). (1)/(n^(2)) + (2)/(n^(2))sec^(2). (4)/(n^(2))+...+1/n sec^(2)1]=

Definite integration as the limit of a sum : lim_(ntooo)[(1)/(n^(2))sec^(2)""(1)/(n^(2))+(2)/(n^(2))sec^(2)""(4)/(n^(2))+.......+(1)/(n)sec^(2)1] a. 'tan1 b. 1/2tan1 c. 1/2sec1 d. 1/2cosec 1

lim_(n rarr oo)[(1)/(n^(2))sec^(2)((pi)/(3n^(2)))+(2)/(n^(2))sec^ (2)((4 pi)/(3n^(2)))+(3)/(n^(2))sec^(2)((9 pi)/(3n^(2)))+. .....+(1)/(n)sec^(2)((pi)/(3))]

lim_(x rarr0)(sec x-1)/(x^(2)(sec x+1)^(2))=

lim_(n to oo) [1/(n^2) "sec"^2 1/(n^2) + 2/(n^2) "sec"^(2) 4/(n^2) + …… + 1/n "sec"^(2) 1] equals :