Find dy/dx in terms of t of the parametric equations x=4e^-2t, y=4 - 2e^2t

x=4e^-2t, y=4-2e^2t

dy/dx = dy/dt * dt/dx

dy/dt = -4e^2t

dx/dt = -8e^-2t           dt/dx = -1/8 * e^2t

dy/dx = (-4e^2t)(-1/8 * e^2t) = 1/2 * e^4t

dy/dx = 0.5e^4t