For the question :
The square root of the fifth root of 4a^4
is the answer:
$\displaystyle 2^\frac15a^\frac25$
that was the answer in my book and i do not understand how to get it.
$\displaystyle \sqrt {\sqrt[5]{{4a^4 }}} = \left( {\left( {4a^4 } \right)^{\frac{1}{5}} } \right)^{\frac{1}{2}} = \left( {\left( {4a^4 } \right)^{\frac{1}{2}} } \right)^{\frac{1}{5}} = \left( {2a^2 } \right)^{\frac{1}{5}} = \left( {2^{\frac{1}{5}} } \right)\left( {a^{\frac{2}{5}} } \right)
$