The roots of the quadratic equation 9y²+my+36=0 are real and equal, f

1.	The roots of the quadratic equation 9y²+my+36=0 are real and equal, find m.
Answer» ANSWER: When ROOTS are real and equal, D = 0 According to the question, $a = 9$ $b = m$ $c = 36$ Using discriminant formula, $\bold{ d = {b}^{2} - 4ac}$ Substitute value of a, b, c $\implies \: 0 = {m}^{2} - (4 \times 9 \times 36)$ $\implies \: 0 = {m}^{2} - {36}^{2}$ $\implies \: {m}^{2} = {36}^{2}$ Taking square ROOT on both SIDES, $\implies {\boxed{ \large \: m = 6}}$