Use chain rule:
dy / dx = ( dy / du ) * ( du / dx )
u = log x
y = log ( log x ) = log u
dy / du = d ( log u ) / du =
1 / u = 1 / log x
( du / dx ) = d ( log x ) / dx = 1 / x
dy / dx = ( dy / du ) * ( du / dx ) =
( 1 / log x ) * ( 1 / x ) =
1 / x log x
y=log(logx) sir this question answer 1/x log x
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