Given that $a > 0$, if $f(g(a)) = 8$, where $f(x) = x^2 + 8$ and $g(x) = x^2 - 4$, what is the value of $a$?
a= @
/||\
>>
Note that
f(0) = 8
Which implires that
x^2 - 4 = 0
x^2 = 4
x = 2 = a
+501 
