## NI If cos (a + b) = 0, then sin (a – b) can be reduced to ​

Question

NI
If cos (a + b) = 0, then sin (a – b) can be reduced to

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1 month 2021-09-17T08:00:30+00:00 1 Answer 0 views 0

Hey mate ! Check ur answer below.

Step-by-step explanation:

From the question, we have cos(a+b)=0

Then,

(a+b)=cos⁻¹(0)

(a+b)=90°

Then,

a=(90°-b)

Now,

sin(a-b)=sin(90-b-b) (from the above calculation)

sin(a-b)=sin(90-2b)

sin(a-b)=cos(2b)

Therefore sin (a – b) can be reduced to cos(2b).

Thank me if u got it

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