Is f(x) = 8x^4+3x^3 + 4x^2+x-4 concave or convex at x=11?
1 Answer
Feb 1, 2018
Concave
Explanation:
The concavity of a function is given by it's third derivative:
When
Let's determine the first derivative:
Given
Now, determine the second derivative:
Plug in
As