Question

Which is not a critical point of the function x^4/4 + 2x^3/3-2x^2-8x in the interval [0, 3]? -2, 2,0, or cos(0)+1?

Answer 1

take the derivative. get

\[x^3+2x^2-4x-8\] which by some miracle factors as
\[(x-2)(x+2)^2\]

Answer 2

so zeros are at 2 and -2 ad those are the critical points.
-2 yes
2, yes
0, no

\[\cos(0)+1=2\] so that is yes as well. what a weird question

Answer 3

lmao. why do you say that :p