Mark the correct alternative in the following:
The function f : R → R is defined by f(x) = cos2 x + sin4 x. Then, f(R) =
f(x)=sin4 x+1-sin2 x
Minimum value of f(x)=3/4
0≤sin2 x≤1
So, maximum value of
=1
R(f)=[3/4, 1]
Answer is C.