Re: ISI 2007 ME-I - Doubts

Posted by sarawagisruti on May 09, 2014; 3:30pm
URL: http://discussion-forum.276.s1.nabble.com/ISI-2007-ME-I-Doubts-tp7588851p7589194.html

Q 29 Given that f is a real-valued differentiable function such that f (x) f ′(x) < 0 for all
real x, it follows that
(A) f (x) is an increasing function;
(B) f (x) is a decreasing function;
(C) f (x) is an increasing function;
(D) f (x) is a decreasing function.