Question

If the roots of the eq. ax square +bx +c=0 are equal then- (1) b square =4bc
(2) a square =4bc
(3) b square =4ac
(4) c square =4ab

Answer 1

$\bf{ \color{red}que{ \color{grey}stion}}$

If the roots of eqn

$\small{ \bf{a {x}^{2} + bx + c = 0}}$

Are equal then

$\small{\bf (1) {b}^{2} = 4bc}$

$\small{ \bf (2) {a}^{2} = 4bc}$

$\small{ \bf{(3) {b}^{2} = 4ac}}$

$\small{ \bf(4){ {c}^{2} = 4ab}}$

$\bf{ \color{blue}ans \color{pink}wer}$

Option (3) is correct

$\tt {b}^{2} = 4ac$

________________________◗ 　

When the roots of eqn are equal

then,

Discriminant (D) = b^2-4ac = 0

so,

$\bf \: {b}^{2} - 4ac = 0 \\ \\ \boxed{ \bf \: {b}^{2} = 4ac}$