**The functions** **$(y=x^2,y=-x^2,y=ax^2 )$**

**$Y=X^2$**

**Properties of the function:**

The most basic quadratic function $b=0$,$c=0$

Minimum, happy face function, its vertex is $(0,0)$

The axis of symmetry of this function is $X=0$.

The function's interval of increase: $X>0$

The function's interval of decrease: $X<0$

Set of positivity: Every $X$ except $0$.

Set of negativity: None. The entire parabola is above the axis$X$.