Question

Let $f(x) = 4x^2 - \sin x + \cos 2x$ for all $x \in \mathbb{R}$. Determine the properties of the function $f$:

• A. a point of local maximum
• B. no point of local minimum
• C. exactly one point of local minimum
• D. at least two points of local minima

Answer 1

Answer: (C)

exactly one point of local minimum

Answer 2

The correct option is (C): exactly one point of local minimum