Question from ISI MSQE 2007:(SEE Q29 of math part.)
Given that f is a real-valued differentiable function such that f(x)f′(x)<0 for all
real x, it follows that :
Ans.(According to Amit Sir's solution:solution)
|f(x)| is a decreasing function .
Is the question asks to work with f(x)*f′(x)<0 or is there some typo? If f(x)*f′(x)<0 is true, I think we should consider two possibilities:
1. f(x)>0 and f'(x)<0 and
2. f(x)<0 and f'(x)>0, right?
Aditya, please help again!
If you reply to this email, your message will be added to the discussion below:
To start a new topic under General Discussions, email [hidden email]
To unsubscribe from General Discussions, click here.