+96 If f(x)={x2−4if x≥−4,x+3otherwise,
then for how many values of x is f(f(x)) = 5?
+130466 f(f(x) either means that
(x^2 - 4)^2 - 4 = 5 or (x + 3) + 3 = 5
x^4 - 8x^2 + 16 - 4 = 5 x + 6 = 5
x^4 - 8x^2 + 7 = 0 x = -1
(x^2 - 7) ( x^2 - 1) = 0 This value of x is not in the domain of the function x + 3 (x must be < -4)
x = ± √7 or x = ± 1
All four values of x
are ≥ -4
So.....four values
