50 баллов,очень надо(( найти dy/dx и d^2y/dx^2 для функции, заданной параметрически: x= t-sint y= 1-cost

dy/dx = dy/dt · dt/dx = dy/dt : dx/dt dy/dt = sint dx/dt = 1 - cost dy/dx = sint/(1-cost) d²y/dx² = d/dx(dy/dx) = d/dt(dy/dx) : dx/dt d/dt(dy/dx) = (cost(1-cost) - sin²t)/(1 - cost)² d²y/dx² = (cost(1-cost) - sin²t)(1 - cost)/[(1 - cost)² sint] = = (cost - cos²t -sin²t)/sint = (cost - 1)/sint d²y/dx²  = (cost - 1)/sint