3 How to solve a first oder ODE with initial condition?

Solve \( y'(x)=1+2 x\) for \(y(x)\) with \(y(0)=3\)

import sympy 
x   = sympy.symbols('x') 
y   = sympy.Function('y') 
ode = sympy.Eq(sympy.Derivative(y(x),x),1+2*x) 
sol = sympy.dsolve(ode,y(x),ics={y(0):3}) 
#    Eq(y(x), x**2 + x + 3) 
sympy.checkodesol(ode,sol) 
#    (True, 0)