Find the maximum and the minimum values (if any) of the function $f(x) = 2x^3 +5$. |
Maximum value: 5; Minimum value: None Maximum value: None; Minimum value: 5 Both maximum and minimum values exist. Neither a maximum nor a minimum value exists. |
Neither a maximum nor a minimum value exists. |
The correct answer is Option (4) → Neither a maximum nor a minimum value exists. Given $f(x) = 2x^3 +5, D_f= R$. Now when $x → ∞, f(x) → ∞$ and when $x → -∞, f(x) → -∞$. Therefore, $f$ has neither maxima nor minima. In fact, f is a strictly increasing function for all $x∈R$. |