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 = 2t/(1+ t^2) and y = (1- t^2)/(1+ t^2)

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

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

Find dy/dx at t = pi/4 , when x = 2 cos 2t and y = 2 sin t - sin 2t

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

Find dy/dx at t = pi/4 when x e^(-t) (sin t + cos t ) and y = e^-t (sin t - cost)

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

Find dy/dx if : y = at^2, t = x/(2a)

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