Let,
y=x2+2x+C
Differentiating both sides w.r.t. x, then we get
y′=(x2+2x+c)′
y′=2x+2+0
y′=2x+2
Taking LHS
y′−2x−2=2x+2−2x−2
y′−2x−2=0
Thus LHS=RHS
Hence verified.
Final answer:
Hence, the function y=x2+2x+C is a solution of the differential equation y′−2x−2=0.