derivate

your answer isn't correct

I think the question is
y = (x-1) (rootx - 2)

y= x(rootx - 2) - 1(rootx - 2)
=xrootx - 2x - rootx +2

now, rootx = x to the power of 1/2
xrootx = x ¹x ^1/2 = x ^(1+1/2) = x ^(3/2)
so
y= x ^(3/2) -2x -x ^(1/2) + 2