Elucidate the slopes of the IS curve and LM curve and their intersection point.

Graphically, the downward -sloping is curve shows an inverse relationship between income (Y) and the "the" interest rate (i), while the upward-sloping LM curve shows a direct relationship between these two variables. describe why these curves have these slopes, what their point of intersection means, and show how expansionary fiscal and monetary policies work. Under what conditions would these policies work more, or less, effectively?