Question

ax+by=a+b,a(x_y)+b (x+y)=2b then find the angle between straight lines​

Answer 1

Answer:

ax+by-(a+b)=0----------1

a1=a,b1=b, c=-a-b

a(x-y)+b(x+y)=2b

a2=a+b,b2=b-a,c2=-2b

cosA=a1a2+b1b2/√a1^2+b^2√a2^2+b^2

         =1/√2

angle =45