Derivative Edition Future Manual Option Other Sixth Solution Student Finding Critical Numbers With The First Derivative Test For Calc I?

Finding critical numbers with the first derivative test for Calc I? - derivative edition future manual option other sixth solution student

I try to find a critical number of equations, and I find, however. The critical number x = -2, 0, 1 However, when I check the book for the correct answer, the critical points x = -2, 1 Why did the book take 0? This is the equation:

f (x) = 2x ^ 3 + 3x ^ 2-12x

There are no restrictions and no way is not defined by f (x). To find the correct answer can be found at calcchat.com. The book will be that I need is the 8th Edition. Chapter 3 Section 3, No. 21 Any help would be appreciated. Thanks