## If f(x) is concave down, then f”(x) is?

### If a function f(x) is concave down, it means that its graph curves downward, resembling a frown

If a function f(x) is concave down, it means that its graph curves downward, resembling a frown. This curvature indicates that the second derivative, f”(x), is negative.

To understand this concept, let’s first review the relationship between the concavity of a function and its second derivative.

When a function is concave up, its graph curves upward like a smiley face. In this case, the second derivative, f”(x), is positive.

Conversely, when a function is concave down, its graph curves downward like a frown. In this case, the second derivative, f”(x), is negative.

The second derivative measures the rate of change of the slope of the function. If the slope of the function is increasing, the second derivative is positive, resulting in a concave up shape. Conversely, if the slope of the function is decreasing, the second derivative is negative, leading to a concave down shape.

Mathematically, we can express the relationship between the concavity of a function and its second derivative as follows:

If f”(x) > 0 for all x in the domain of f(x), then f(x) is concave up.

If f”(x) < 0 for all x in the domain of f(x), then f(x) is concave down. Therefore, if f(x) is concave down, we can conclude that f''(x) < 0.

## More Answers:

The Relationship Between an Increasing Function and Its Derivative: ExplainedUnderstanding the Relationship Between a Decreasing Function and Its Derivative: Explained Mathematically

Why is the Second Derivative Positive if a Function is Concave Up in Mathematics?