DETERMINE IF THE FUNCTION IS DIFFERENTIABLE FROM THE GRAPH

Check If the Function is Differentiable from the Graph

A function is not differentiable at x = a under any of the following conditions.

1) The function has discontinuity.

2) The graph of the function has a sharp corner or cusp.

3) The tangent line at x = a has a vertical slope.

Determine whether the following function is continuous, differentiable, neither or both at the point.

Problem 1 :

from-the-graph-differentiable-q1

Solution :

lim x3-f(x)=undefinedlim x3+f(x)=definedlim x3-f(x)lim x3+f(x)

The function is not continuous, it is not differentiable. It has jump discontinuity. So, it is neither.

Problem 2 :

from-the-graph-differentiable-q2.png

Solution :

lim x1-f(x)=undefinedlim x1+f(x)=undefined

The function has removable discontinuity. The function f(x) is discontinuous, then it is not differentiable.

So, it is neither.

Problem 3 :

from-the-graph-differentiable-q3.png

Solution :

lim x0-f(x)=lim x0+f(x)

The function is continuous, it is differentiable. So, it is both.

Problem 4 :

from-the-graph-differentiable-q4.png

Solution :

The function is continuous, at x = 0, we see the vertical tangent. So, the function is continuous but not differentiable at the point x = 0.

Problem 5 :

from-the-graph-differentiable-q5.png

Solution :

The function is discontinuous at x = 2, it has infinite discontinuity. So, the function is discontinuous and it is not differentiable. Then it is both.

Problem 6 :

from-the-graph-differentiable-q6.png

Solution :

The function is continuous. Since we have sharp point at x = 0. The function is not differentiable. So, the function is continuous but not differentiable.

Problem 7 :

from-the-graph-differentiable-q7.png

Solution :

The function is continuous. At x = 2, we can draw the vertical tangent line. Then the function is continuous but not differentiable at the point x = 2.

Problem 8 :

from-the-graph-differentiable-q8.png

Solution :

The function is continuous. At x = -1, we can draw the vertical tangent line. Then the function is continuous but not differentiable at the point x = -1.

Recent Articles

  1. Finding Range of Values Inequality Problems

    May 21, 24 08:51 PM

    Finding Range of Values Inequality Problems

    Read More

  2. Solving Two Step Inequality Word Problems

    May 21, 24 08:51 AM

    Solving Two Step Inequality Word Problems

    Read More

  3. Exponential Function Context and Data Modeling

    May 20, 24 10:45 PM

    Exponential Function Context and Data Modeling

    Read More