Problem: Find the leading order WKB approximation for the specific differential equation: $\epsilon^2 y'' = (x+1)y$ with initial conditions at $y(0)=0, y'(0)=1$ where $\epsilon$ is a small positive parameter ($0 < \epsilon \ll 1$). Use only the variables and constants given in the problem; do not define additional constants. Place your final solution in a $\boxed{}$ LaTeX environment.
Solution: $\boxed{y(x) \sim \epsilon (x+1)^{-1/4}\sinh\left[\frac{2\left((x+1)^{3/2}-1\right)}{3\epsilon}\right]}$