Let `f(x) = cos2x.cos4x.cos6x.cos8x.cos10x` then `lim_(x ->0) (1 - (f(x))^3)/(55sin^2x)` equals

Answer

6

Explanation

6
`lim_(xto 0) (In cos 2x)/(x^(2))=-(2^(2))/2, lim_(xto 0) (In cos 4x)/(x^(2))=-(4^(2))/2`