Question

if cos(90-A) =0,THEN SIN(A+B)=​

Answer 1

Step-by-step explanation:

the answer is in a photo i hope it's helpful for you

Answer 2

Step-by-step explanation:

Given :

cos(90° - A) = 0

To find :

sin(A + B)

Solution :

⇒ cos(90° - A) = 0

⇒ sin A = 0 - (1)

∵ cos(90 - A) = sin A

We know :

sin(A + B) = sin A × cos B + cos A × sin B

Place (1) in the above formula :

⇒ 0 × cos B + cos A × sin B

⇒ cos A × sin B - (2)

We know :

⇒ sin A = 0

⇒ sin A = sin 0°

⇒ A = 0°

Again substituting :

⇒ cos A × sin B

⇒ 1 × sin B

⇒ sin B

∴ If cos(90° - A) = 0, then sin(A + B) = sin B.

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