Second Derivative Test Calculator



The Second Derivative Test is a powerful tool in calculus for analyzing the concavity and identifying critical points of a function. Understanding this test is crucial for determining the nature of extrema (maxima or minima) in mathematical functions. The Second Derivative Test Calculator simplifies this process, offering a convenient way to evaluate the second derivative of a function at a given point and interpret the results.


The Second Derivative Test involves the examination of the sign of the second derivative at a critical point. The formula is as follows:

  • If >0, then the function has a local minimum at .
  • If <0, then the function has a local maximum at .
  • If =0, the test is inconclusive.

How to Use?

Using the Second Derivative Test Calculator involves the following steps:

  1. Input the Function: Enter the mathematical function into the calculator.
  2. Find the Critical Points: Determine the critical points of the function by finding where the first derivative is equal to zero or undefined.
  3. Calculate the Second Derivative: Obtain the second derivative of the function.
  4. Evaluate at Critical Points: Substitute the critical points into the second derivative to determine its sign.
  5. Interpret Results: Based on the sign of the second derivative at each critical point, identify whether the function has a local minimum, maximum, or if the test is inconclusive.


Consider the function 3−6 2+9+1.

  1. Find the critical points by setting =0.

    3 2−12+9

    Solve for : =1 and =3.

  2. Calculate the second derivative:


  3. Evaluate the second derivative at the critical points:

    ′′(1)=−6 (negative, indicating a local maximum)

    ′′(3)=6 (positive, indicating a local minimum)

So, according to the Second Derivative Test, the function has a local maximum at =1 and a local minimum at =3.


Q1: Can the Second Derivative Test be applied to any function?

A1: The test is applicable to differentiable functions, but certain conditions must be met for its validity.

Q2: What does it mean if the second derivative is zero at a critical point?

A2: If ′′()=0, the Second Derivative Test is inconclusive, and further analysis may be required.

Q3: How does the Second Derivative Test relate to the First Derivative Test?

A3: Both tests help analyze the behavior of a function around critical points, but they focus on different aspects—concavity for the Second Derivative Test and slopes for the First Derivative Test.


The Second Derivative Test Calculator serves as a valuable tool for students, mathematicians, and anyone dealing with mathematical functions. By understanding the second derivative’s role in determining concavity and using the calculator to assess critical points, users can gain insights into the nature of extrema in a function and enhance their comprehension of calculus concepts.

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