(A) cos x
(B) cos 2x
(C) cos 3x
(D) tan x
13 On which of the following intervals is the function f given by f (x) = x100 + sin x –1
decreasing (A) (0,1)
(B)
 π2,
π 
 
 
 
 
(C)
0, 2
π
 
 
 
 
 
 
(D) None of these
14 For what values of a the function f given by f (x) = x2 + ax + 1 is increasing on
[1, 2]