23. On a circle with center at point $O$, there is a point $X$. On the diameter extending from point $X$, take point $Y$ such that $O$ lies between $X$ and $Y$. It is required to draw a chord $AB$ through point $Y$ so that $\angle A X B$ is minimized.
74.23. Answer. The chord $A B$ should be drawn perpendicular to the line $O X$.