If f(x) = |x − 25| and g(x) = f(f(x)) then for x > 50, g'(x) is equal to

0 1 25 None of these

1

$g(x)=f(f(x))=f(|x-25|)=||x-25|-25|$ for $x>50, ~g(x)=|x-25-25|=|x-50|=x-50, ~g'(x)=1$ Hence (1) is the correct answer.