Let the roots of given equation be m and n
According to the question M = n
Sum of roots = m + n = – b / a
\(2m=-b/a\)
\(\Rightarrow m=-b/2a\)
Product of roots = m × n = \(c/a\)
m2 = \(c/a\)
\((-b/2a)^2=c/a\)
\(b^2/4a^2=c/a\)
\(b^2/4a^2=c\)
Therefore c = \(\frac{b^2}{4a}\)