Question

sin( A-B )+ sin A+B/cos (A+B )+ cos(A-B)= tan A
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Answer 1

Answer:

Step-by-step explanation:

Since,

sin(x+y) = sinx × cosy + cosx × siny

sin(x-y) = sinx × cosy - cosx × siny

cos(x+y) = cosx × cosy - sinx × siny

cos(x-y) = cosx × cosy + sinx × siny

We have to prove that,

sinacosb+cosasinb+sinacosb-cosasinb/cosacosb-sinasinb

2sinacosb/2cosacosb

tan a