If f(x)=|x−2|,g(x)=f(f(x)) then for 2<x<4,g′(x) is
-1
1
2
3
fx=x−2,for2<x<4−x−2,forx<2
∴gx=ffx=fx−2=x−2−2=−x−4,2<x<4. ∴g'x=−1