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For the function f(x)=∣x+1∣+∣x−1∣+∣x−2∣f(x) = |x + 1| + |x - 1| + |x - 2| which of the following are TRUE?

A. f(x)f(x) is continous on R\mathbb{R}

B. f(x)f(x) is not differentiable at x=1x = 1

C. f(x)f(x) is differentiable on R\mathbb{R}

D. f(x)f(x) has no local maxima

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 1

A sum of modulus functions is continuous everywhere, so A holds and C fails (corners at x=−1,1,2x=-1,1,2), which also makes B true.

The slopes on successive pieces are −3,−1,1,3-3,-1,1,3, so ff falls then rises with a single minimum at x=1x=1 and no local maximum, giving D. Hence A, B and D.

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