Find the intervals in which the function f(x) = sin^4x + cos^4x

CBSE Class 12
1

Find the intervals in which the function f(x) = sin4x + cos4x is increasing or decreasing where the range of x is ( 0, pie/2).

2

f(x) = sin4 x + cos4 x
Find f’(x) we get
f’(x) = -2sin2x cos2x
f’(x) = -sin4x
As x is in the interval [0, π/2] hence 4x is in the interval [0, 2π]
image