Question

If $f(x) = |x - 2|$ and $g(x) = f(f(x))$, then for x>20, $g^{'}(x)$ equals

• A. –1
• B. 1
• C. 0
• D. None of these

Answer 1

Answer: (B)

1

Answer 2

For x > 20, we have $f(x) = |x - 2| = x - 2$ and,

$g(x) = f(f(x)) = f(x - 2) = x - 2 - 2 = x - 4$

∴ $g^{'}(x) = 1$