Question
Mathematics Question on Differential equations
The minimum value of f(x)=sin4x+cos4x,0≤x≤π2
A
(A) 122
B
(B) 1414
C
(C) −12
D
(D) 12
Answer
(D) 12
Explanation
Solution
Explanation:
∵f(x)=sin4x+cos4x=(sin2x+cos2x)2−2sin2x⋅cos2x⇒f(x)=1−12sin22x Also 0≤sin22x≤1∴ Minimum value of f(x)1−12=12