Question

If sin theeta =1, then cos 2 theeta =​

Answer 1

Answer:

-1

Step-by-step explanation:

sinθ = 1

We know that sin90° = 1

∴ sinθ = sin90°

∴ θ = 90°

∴ cos2θ

 ⇒ cos2(90°)

 ⇒ cos180°

 ⇒ -1