Q.

Let f(x)=17-sin5x be a function defined on R. Then the range of the function f(x) is equal to :                [2024]

1 [17,15]  
2 [17,16]  
3 [18,16]  
4 [18,15]  

Ans.

(3)

   Since, -1≤sinθ≤1 ∀θ, so we have

   -1≤sin 5x≤1

   ⇒-1≤-sin5x≤1

   ⇒-1+7≤7-sin5x≤1+7

   ⇒18≤17-sin5x≤16

   ⇒Range f(x)=[18,16]