Question

if cos x + sec x = 2 then for positive integer n, cos rais to n x + sec rais to n x is equal to
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Answer 1

If cosx+secx=−2

cosx+

cosx

1

=−2

cos

2

x+1=−2cosx

⇒(cosx+1)

2

=0

⇒cosx=−1

⇒cos

n

x+sec

n

x=−2 if n is odd

⇒cos

n

x+sec

n

x=2 if n is even