Computing the integral $\int_{-1}^{2} \left( |x| + |1-x| \right) {\rm d} x$ I'm having trouble with one of the exercises, I have to split the integral for the absolute value but I can't manage to algebraic find the boundaries for the integral.
$$\int_{-1}^{2} \left( |x| + |1-x| \right) {\rm d} x$$
Thanks in advance!

$$\int_{-1}^2 dx (|x|+|1-x|) = \int_{-1}^0 dx (-x + 1-x) + \int_0^1 dx (x+1-x) + \int_1^2 dx [x-(1-x)] $$
Go...
