Question 284056
Just like everything else in algebra, work from the inside out<br>
{{{ f(x)=x^2 }}}
{{{ g(x)=2^x }}}  <br>
{{{ g^-1(f(3)) }}} rewritten as {{{ g(f(3))^(-1) }}}
{{{ f(3) = 3^2 = 9 }}}
{{{ g(9) = 2^9 = 512 }}}
{{{ 512^(-1) = 1/512 }}} or approximately {{{ 0.001953 }}} 
<i> and bob's your uncle!</i>