The function f (x) =x3 has aa)point of inflexion at = 0b)local minima ...
f ‘(0) = 0 , f ‘’ (0) = 0 and f ‘’’(0) = 6 . So, f has a point of inflexion at 0.
View all questions of this testThe function f (x) =x3 has aa)point of inflexion at = 0b)local minima ...
Explanation:
To determine the points of inflection, local minima, and local maxima of a function, we need to analyze its second derivative.
The given function is f(x) = x^3.
First Derivative:
To find the first derivative of f(x), we differentiate the function with respect to x.
f'(x) = 3x^2
Second Derivative:
To find the second derivative of f(x), we differentiate the first derivative with respect to x.
f''(x) = d/dx(3x^2) = 6x
Analysis:
To determine the points of inflection, local minima, and local maxima, we need to analyze the sign of the second derivative.
If the second derivative is positive, the function is concave up, and there is a local minimum.
If the second derivative is negative, the function is concave down, and there is a local maximum.
If the second derivative changes sign from positive to negative or vice versa, there is a point of inflection.
Checking for Points of Inflection:
Since the second derivative f''(x) = 6x is a linear function, it does not change sign. Therefore, there are no points of inflection in the function f(x) = x^3.
Checking for Local Minima/Maxima:
To find the local minima/maxima, we need to analyze the sign of the first derivative.
If the first derivative changes sign from positive to negative, there is a local maximum.
If the first derivative changes sign from negative to positive, there is a local minimum.
In our case, the first derivative f'(x) = 3x^2 is always positive or zero for all x. This means that there are no sign changes in the first derivative, indicating that there are no local minima or maxima in the function f(x) = x^3.
Conclusion:
Based on the analysis of the second derivative and the first derivative, we can conclude that the function f(x) = x^3 has no points of inflection, no local minima, and no local maxima. Therefore, the correct answer is option 'A' - none of these.