Let

be an acute triangle. Denote by

and

the feet of the altitudes from vertices

and

, respectively. Let

be a point inside the triangle

such that the line

is tangent to the circumcircle of the triangle

and the line

is tangent to the circumcircle of the triangle

. Show that the line

is perpendicular to

.
%V0
Let $ABC$ be an acute triangle. Denote by $B_0$ and $C_0$ the feet of the altitudes from vertices $B$ and $C$, respectively. Let $X$ be a point inside the triangle $ABC$ such that the line $BX$ is tangent to the circumcircle of the triangle $AXC_0$ and the line $CX$ is tangent to the circumcircle of the triangle $AXB_0$. Show that the line $AX$ is perpendicular to $BC$.