Question

. If cos (a + b) = 0, then sin(a - b) = ?
(al cos
h cos 20​

Answer 1

Answer:

the ans will be cos theata +asin-b cos

Answer 2

Option B is correct.

Step-by-step explanation:

Given that cos(a+b)=0

then we have to find the reduced form of sin(a-b)

As, cos(a+b)=0cos(a+b)=0

⇒ a+b=cos^{-1}(0)=90^{\circ}a+b=cos−1(0)=90∘

⇒ a=(90-b)^{\circ}a=(90−b)∘

sin(a-b)=sin(90-b-b)=sin(90-2b)=cos{2b}sin(a−b)=sin(90−b−b)=sin(90−2b)=cos2b

Hence, sin(a-b)=cos{2b}

∴ option b) is correct