Which of the following is a general solution to the Clairaut equation y=xy′+f(y′)y = xy' + f(y')y=xy′+f(y′)?
y=cx+f(c)y = cx + f(c)y=cx+f(c)
y=c2x+f(c)y = c^2x + f(c)y=c2x+f(c)
y=cx+f(x)y = cx + f(x)y=cx+f(x)
y=c2x2+f(c)y = c^2x^2 + f(c)y=c2x2+f(c)