so it says:
Sketch y = x^2 and mark the points A(a, a^2), B(-a, a^2), P(a,0) and Q(-a, 0).
a) show that the integral from 0 to a of x^2 dx (sorry, can't insert the sign) = 2/3 (area of triangle OAP)
b) show that the integral from -a to a of x^2 dx = 1/3 (area of rectangle ABQP)
i'm not sure...