DifferentiationHard
Question
If y = cos-1 (cos x), then 
at x = 
is equal to
at x = is equal to Options
A.1
B.-1
C.1/√2
D.-1/√2
Solution
y = cos-1 (cos x)
∵ x =
⇒ y = cos-1 (cos (2π - x))
⇒ y = 2π - x
= - 1
∵ x =
⇒ y = cos-1 (cos (2π - x))
⇒ y = 2π - x
= - 1Create a free account to view solution
View Solution Free