posted by Liz .
Find an equation of the line that is tangent to the graph of f and parallel to the given line.
f'=-1/2 * (x-1)^-1.5
that is the slope then tangent to the line.
so slope is -1/2
f'=-1/2 * (x-1)^-3/2=-1/2
y=1/sqrt(x-1)=1 so the point of tangency is 2,1
check all this.