Write the number of quadratic equations, with real roots, which do not change by squaring their roots.
from the given condition roots remain unchanged only when they are equal to 1 and 0.
Hence the roots may be (0,1) or (1,0) and (1,1) and (0,0).
Hence 3 equations can be formed by substituting these points in (x-a) (x-b) = 0
Where a, b are roots or points.