If one of the lines of the pair $a{x}^2+2hxy+b{y}^2=0$ bisects the angle between positive direction of the axes then a, b, h satisfy the relation

Given equation  $a{x}^2+2hxy+b{y}^2=0$ --(1)

Bisector of Angle b/w coordinate axis are $y=\pm x$ 

If(1 ) are sub y = x in bisects angle b/w positive direction of the axes

$\begin{array}{l}\Rightarrow a{x}^2+2h{x}^2+b{x}^2=0\\ \Rightarrow x^2\left(a+2h+b\right)=0\\ \therefore x^2\ne 0,\Rightarrow a+2h+b=0\end{array}$