1.
Let f:[1,2]Rf : [-1,2] \to \mathbb{R} be given by f(x)=2x2+x+[x2][x]f(x) = 2x^2 + x + [x^2] - [x], where [t][t] denotes the greatest integer less than or equal to tt. The number of points where ff is not continuous, is: