Question

If a×cos x + b × cos x = c, then the value of (a × sin x – b²cos x)² is

Answer 1

Answer:

Correct option is

A

2∣b∣

1

d

2

−a

2

asinx+bcos(x+θ)+bcos(x−θ)=d

⇒asinx+2b⋅cosx⋅cosθ=d

⇒∣d∣≤

a

2

+4b

2

cos

2

θ

⇒

4b

2

d

2

−a

2

≤cos

2

θ

⇒∣cosθ∣≥

2∣b∣

d

2

−a

2

.