Question

If cos(p-q)/cos(p+q)=-cos(r+s)/cos(r-s) then prove that tan(p)×tan(q)-tan(r)×tan(s)=0​

Answer 1

cos(p-q)/cos(p+q)=-cos(r+s)/cos(r-s) then prove that tan(p)×tan(q)-tan(r)×tan(s)=0