isi

Posted by Seecha on May 02, 2017; 12:14pm
URL: http://discussion-forum.276.s1.nabble.com/isi-tp7603892.html

27. Let f : R → R be a differentiable function such that f(x)f'(x) < 0 for all x ∈ R. Then
A. f(x) is an increasing function B. |f(x)| is an increasing function C. f(x) is a
decreasing function D. |f(x)| is a decreasing function
.
.
.
answr is d . how ?