Solve `x^(2) lt "sin" pi/2 x`.

Explanation

We have `x^(2) lt "sin" pi/2 x`
Function `y="sin"pi/2x` has period `(2pi)/(pi//2)=4`
Graphs of `y=x^(2)` and `y="sin" pi/2 x` are as shown in the following figure.

Graphs of the functions intersect at two points (0, 0) and (1, 1)
From the figure, `x^(2) lt "sin" pi/2 x` for `x in (0, 1)`