What is the area between the curve f(x) = x |x| and x-axis for x = [-1, 1]?

What are the order and the degree respectively of the differential equation $\rm x^2\left(\frac{d^3 y}{d x^3}\right)^2+\left(\frac{d y}{d x}\right)^4+\sin x=0$ ? 

What is the differential equation of all parabolas of the type y2 = 4a (x - b)?

Consider the following for the next items that follow:

Let a1, a2, a3 ... be in AP such that a1 + a5 + a10 + a15 + a20 + a25 + a30 + a34 = 300.

What is a1 + a5 - a10 - a15 - a20 - a25 + a30 + a34 equal to ?