Find an equation for the line tangent to the curve at the point defined by the given value of $t$. Also, find the value of $\frac{d^2y}{dx^2}$ at this point.
$x = t - \sin t$, $y = 1 - 3 \cos t$, $t = \frac{\pi}{3}$
Write the equation of the tangent line
y = \boxed{}x + \boxed{}
(Type exact answers, using $\pi$ as needed.)
What is the value of $\frac{d^2y}{dx^2}$ at this point?
$\frac{d^2y}{dx^2} = \boxed{}$ (Type an integer or a simplified fraction.)
