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State the first derivative test for critical points. Use concavity and inflection points to explain how the sign of the second derivative affects the shape of a function’s graph. Explain the concavity test for a function over an open interval.
Dec 21, 2020 · Interval 2, \((-1,0)\): For any number \(c\) in this interval, the term \(2c\) in the numerator will be negative, the term \((c^2+3)\) in the numerator will be positive, and the term \((c^2-1)^3\) in the denominator will be negative. Thus \(f''(c)>0\) and \(f\) is concave up on this interval.
Review your knowledge of concavity of functions and how we use differential calculus to analyze it.
- You have two functions f and g, where f''>0 and g''>0. If you take the second derivative of f+g, you get f''+g'', which is positive. So their sum i...
- In order for 𝑓(𝑥) to be concave up, in some interval, 𝑓 ''(𝑥) has to be greater than or equal to 0 (i.e. non-negative) for all 𝑥 in that inter...
- In general, no. Points where f"(x)= 0 are specifically called inflection points. But in the example provided, -2 is also a critical point (Observe...
- Product rule: d/dx[f(x)*g(x)] = f'(x)g(x) + f(x)g'(x) f(x) = (x-1)³ and g(x) = x
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If \( f''(x) \) is positive on an interval, the graph of \( y=f(x) \) is concave up on that interval. We can say that \(f\) is increasing (or decreasing) at an increasing rate. If \( f''(x) \) is negative on an interval, the graph of \( y=f(x) \) is concave down on that interval.
Let y = f (x) y = f (x). The second derivative of f f is the derivative of y′ =f ′(x) y ′ = f ′ (x). Using prime notation, this is f ′′(x) f ″ (x) or y′′ y ″. You can read this aloud as “f double prime of x” or “y double prime.” Using Leibniz notation, the second derivative is written d2y dx2 d 2 y d x 2 or d2f dx2 d 2 f d x 2.
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How do you determine the concavity of a function?
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What is the concavity of a function?
If given a graph of f (x) or f' (x), determining concavity is relatively simple. Otherwise, the most reliable way to determine concavity is to use the second derivative of the function; the steps for doing so as well as an example are located at the bottom of the page.
