Question

If the period of f(x) = , n ∈ N is 6π, then n is equal to

• A. 3
• B. 2
• C. 6
• D. 1

Answer 1

Answer: (C)

6

Answer 2

Period of cos(sinnx) is and period of is π.n. Thus 6π = L.C.M.$\left( \frac { \pi } { n } , \pi n \right)$

⇒

and 6π =λ₂ . πn ⇒

where λ₁, λ₂ ∈ I⁺

From we get n = 6, 3, 2, 1

Clearly for n = 6, we get period of f(x) to be 6π.