Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The joint equation of two altitudes of an equilateral triangle is $(\sqrt{3} x-y+8-4 \sqrt{3})(-\sqrt{3} x-y+12+4 \sqrt{3})=0$ The third altitude has the equation

Straight Lines

Solution:

Clearly, the third altitude will be the bisector of obtuse angle between the given altitudes.
Now given two altitudes are
$ \sqrt{3} x-y+8-4 \sqrt{3}=0 $ .... (i)
and $ -\sqrt{3} x-y+12+4 \sqrt{3}=0$ .....(ii)
$ a_{1} a_{2}+b_{1} b_{2}=-\sqrt{3} \sqrt{3}+(-1)(-1)=-2<0$
$\therefore $ Obtuse angle bisector is:
$\frac{\sqrt{3} x-y+8-4 \sqrt{3}}{3+1}=-\frac{-\sqrt{3} x-y+12+4 \sqrt{3}}{3+1}$
or $ y=10$