Find the points where the function is not differentiable

  1. 1. The problem statement, all variables and given/known data
    Find the points where the function given by
    [​IMG]
    is not differentiable.

    3. The attempt at a solution

    I got the doubtful points as +-1, 2
    How do I check the differentiability now? The mod. function is confusing me a bit.
     
  2. jcsd
  3. micromass

    micromass 18,543
    Staff Emeritus
    Science Advisor

    You should transform this function in a piecewize function.

    That is, the doubtfull points are those when x2-3x+2=0 and x=0.
    Once you've determined these points, you can write your function is piecewise form...
     
  4. My book says 1,-1,2 are the possible points of non-differentiability.
    Can you tell me how -1 is included?
    Moreover, 0 as you told would not be a doubt full point as cos(modx) is same as cosx
     
  5. micromass

    micromass 18,543
    Staff Emeritus
    Science Advisor

    -1 is not a point of non-differentiability, at least not if you follow my method. Maybe the book uses other methods.

    You are correct about 0. Thus 1 and 2 are the only possible points of non-differentiability...
     
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