Mathematics

Problem

Which statement correctly describes the concavity of the graph of

y=\ln x

for

x>0

? a) It is concave upward for all

x>0

. b) It is concave downward for

x>1

and concave upward for

0<x<1

.},{ c) It is concave downward for all

x>0

. d) It changes concavity at

x=1

.}],