1) The value of cos(12cos−118) is equal to A) -3/4 B) 3/4 C) 1/16 D) 1/4 Answer: Option BExplanation:Let cos−118=θ,where0<θ<π2 ⇒12cos−118=12θ, ⇒cos(12cos−118)=cos12θ, Now, cos−118=θ⇒cosθ=18 ⇒2cos2θ2−1=18 ⇒cos2θ2=916⇒cosθ2=34 [∵0<θ2<π4,socosθ2≠−34]