Prove that the following functions do not have maxima or minima:
h(x) = x3 + x2 + x +1
h(x) = x3 + x2 + x +1
⇒ h’(x) = 3x2 + 2x +1
h(x) = 0
⇒ 3x2 + 2x +1 = 0
Therefore, there does not exist c ϵ R such that h’(c) = 0
Hence, function h does not have maxima or minima.