Consider the following statements: I. The function is increasing in the interval (-\infty, \infty). II. The function is differentiable at x=0. Which of the statements given above is/are correct?
For the following three (03) items: Consider the function f(x)=x|x|.
- A. I only
- B. II only
- C. Both I and II ✓
- D. Neither I nor II
Correct Answer: C. Both I and II
Explanation
The function can be written as f(x) = x^2 for x \geq 0 and -x^2 for x \lt 0. Its derivative is f'(x) = 2x for x \geq 0 and -2x for x \lt 0, meaning f'(x) = 2|x|. Since f'(x) \geq 0 for all real x, the function is strictly increasing on (-\infty, \infty). Also, the left and right hand derivatives at x=0 are both 0, making it differentiable at x=0. Thus, both statements are correct.
Related questions on Calculus
- Let z=[y] and y=[x]-x, where [.] is the greatest integer function. If x is <strong>NOT</strong> an integer but positive, then what i...
- If f(x)=4x+1 and g(x)=kx+2 such that fog(x)=gof(x), then what is the value of k?
- What is the <strong>MINIMUM</strong> value of the function f(x)=\log_{10}(x^{2}+2x+11)?
- What is \int(x^{x})^{2}(1+\ln x)\,dx equal to ?
- What is \int e^{x}\{1+\ln x+x\ln x\}\,dx equal to?