Calculus | Minimum of Crease |Calculate the Derivative

[chrisjones]

There are multiple errors in the math in this video. You might want to take a second look at what you've done in your differentiation. In your chain rule differentiation you should have had 12x³-51x²-4x³. I
This reduces to 8x³-51x². You have 6x³ instead of 8x³, which then made your domain impossible to satisfy. The fact that you didn't catch the mistake on substitution makes me think you may have copied this problem from elsewhere and simply tried to reproduce it. I appreciate the attempt at explaining it anyway.