Question

Why we make c1 and c2 same sign on finding equation of angle bisectors?

Answer 1

Answer:

Step-by-step explanation:

Let the 2 Lines be

A1x + B1y + C1 =0 and

A2x +B2y + C2 = 0

The 2 angle bisectors of the lines above are

To find the acute angle bisector, we need to make C1 and C2 of the same sign, then if

(A1)(A2) +(B1)(B2) < 0. Use the + sign on the RHS and vice versa. i.e.