Attached is a picture. Notice that there is a local minimum at x = − 0.4 {\displaystyle \displaystyle x=-0.4} and a local maximum at x = − 1.4 {\displaystyle \displaystyle x=-1.4} . Also note that plugging in a into the integral gives
A ( a ) = ∫ a a f ( s ) d s = 0 {\displaystyle \displaystyle A(a)=\int _{a}^{a}f(s)\,ds=0} .
