Question

solve 1 + cos ( x - y )​

Answer 1

Answer:

Given, 1+cos(x−y)=0⇒1+2cos2(2x−y)−1=0

cos(2x−y)=0⇒(2x−y)=2π⇒x−y=π

⇒x=π+y

Taking cos both sides on x=π+y

cosx=cos(π+y)=−cosy⇒cosx+cosy=0

Taking sin both sides on x=π+y

sinx=sin(π+y)=−siny⇒sinx+siny=0