The following Simulink model solves the differential equation t - 4x(t) = x''(t), and generates the plot below for x(t). But the plot doesn't look like a plot of t/4 + C1 * cos(2t) -C2*sin(2t), which is x(t). For example, if C1 and C2 are set equal to 1 a different plot is generated. How is the Simulink plot to be interpreted? No initial conditions are specified and it appears that x(0) = 0 and x'(0) = 0 are assumed but it seems that with these initial conditions the differential equation has no solution because the output of Matlab when I specified these initial conditions, or only the condition x(0) == 0, to solve the differential equation with dsolve was empty.