Find `dy/dx when `x = 2t/(1+ t^2)` and `y = (1- t^2)/(1+ t^2)`

Find dy/dx when x = 4t, y = 4/t

Find dy/dx at t = 2 when x = (2bt)/(1+t^2) and y = (a(1-t^2))/(1+t^2)

Find dy/dx , when: x = a(1-t^2)/(1+t^2), y = b (2t)/(I+t^2) .

Find dy/dx when x = t + 1/t, y = t - 1/t

Find dy/dx, where x=t^3 + 1/t and y = (t+t^2)^3

Find dy/dx when x = a sin^2 t, y = b cos^2 t

For a positive constant a find dy/dx ,where y = a^(t+(1/t)), and x = (t + 1/t)^a

Find (dy)/(dx) in the following x = (1 - t^2)/(1 + t^2), y = (2t)/(1 + t^2)

Find dy/dx , if x and y are connected parametrically by the equations, given below without eliminating the parameter. x = -(2t)/(1+t^2), y = (1-t^2)/(1+t^2)

If sinx = (2t)/(1+t^2), tan y = (2t)/(1-t^2) , find dy/dx