Boundary Curvature From a Nonzero Slope Condition

Suppose u(0)=4, u_1=5, h=0.25, and the left-boundary slope satisfies u_x(0)=-2 approximated by (u_1-u_{-1})/(2h). What second derivative estimate do you get from (u_{-1} - 2u_0 + u_1)/h^2?