If f : D →R f(x)=x2+bx+cx2+b1x+c1, where α, β are th roots of the equation x2+bx+c=0 and α1, β1 are the roots of x2+b1x+c1=0. Now, answer the following question for f(x). A combination of graphical and analytical approach may be helpful in solving these problems. If α1 and β1 are real, then f(x) has vertical asymptote at x=(α1, β1).
If the equations x2 + bx + c = 0 and x2+b1x+c1=0 do not have real roots, then
f'(x) = 0 has real and distinct roots
f(x) has one of the two graphs
⇒ f'(x) = 0 has real and distinct roots.