(1) Given the curve x=6t^2 , y=t^3 -2t where t is not = 0, show that dy/dx = (t^2 -1)/4t. Hence, find the point in the curve at which the tangents to the curve and parallel to the x-axis.

(2) y= (2x-5)/(x^2 -4) . Prove that y>=1 or y<= for all real values of x.

(3) Sketch the curve of y^2 = x^2 (1-x).

Please show me the steps about how can i solve these. Especially about the graph sketching part. Thanks.