UPSC NDA Math Model Paper 1

Given:
f(x)=|x−1|
⇒f(x)=|x−1| ={

−(x−1),	x<1
x−1,	x≥1

We have to find the derivative of |x - 1| at x = 2
It means we have to take f(x) for x ≥ 1
Therefore, f(x) = x - 1
Differentiating with respect to x, we get
⇒ f'(x) = 1