If sinθ + cosθ = 1, then sinθ. cosθ.

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If sinθ + cosθ = 1, then sinθ. cosθ. is equal to

1. 0
2. 1
3. 1
  2
4. − 1
  2

Correct Option: A

sinθ + cosθ = 1
On squaring,
(sinθ + cosθ) = 1
⇒ sin²θ + cos²θ + 2 sinθ. cosθ = 1
⇒ 1 + 2 sinθ . cosθ = 1
⇒ 2 sinθ . cosθ = 1 – 1 = 0
⇒ sinθ. cosθ = 0

−	1
	2