Question

l sin theta + m cos theta + n = 0; l' sin theta + m' cos theta + n' = 0
prove that :-
(l m'+l'm)*(l m'+ l'm) + (l m'-l'm)*(l m'-l'm)=(n l + n' m)

Answer 1

Ab iske bad sin theta + cos theta karke sign change krke LCM le or solve krlo Agr nahi ho to batana
hope this ☝☝may help u