Asked by John

Find the critical numbers of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.)
f(x) = 4x3 + x2 + 4x
Answered by Steve
well, f'(x) = 12x^2+2x+4 = 2(6x^2+x+2)

so, keeping in mind the definition of critical numbers, whet do you think?
Answered by Dr. Math
you can't factor it and also can't quadratic 4X^3+X^2+4X so the answer is none(DNE).