A quadratic equation ax^2+ bx + c = 0, has coincident roots, if : - Vidyadip

MCQ

A quadratic equation $ax^2+ bx + c = 0,$ has coincident roots, if :

A
$ b^2-4 a c<0 $
B
$ b^2-4 a c>0 $
✓
$ b^2-4 a c=0 $
D
$ b^2-a c=0 $

✓

Answer

Correct option: C.

$ b^2-4 a c=0 $

The roots of the quadratic equation $a x^2+b x+c=0$, In this formula the term $b^2-4 a c$ is called the discriminant.
If $b^2-4 a c=0$ so the equation has a single repeated root.
If $b^2-4 a c>0$, the equation has two real roots.
If $b^2-4 a c<0,$ the equation has two complex roots.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Quadratic Equations→Quadratic Equations — all question types→Maths STD 10 question papers→CBSE Board STD 10 question papers→CBSE Board question paper generator→

Similar questions

Mark the correct alternative in the following : If $\mathrm{S}_{\mathrm{r}}$ denotes the sum of the first $r$ terms of an $A.P$. Then, $S_{3 n}:\left(S_{2 n}-S_n\right)$ is :

If the first, second and last terms of an $A.P.$ are $a, b$ and $2 a$ respectively, its sum is

If $\alpha, \beta$ are the zeros of polynomial $f(x)=x^2-p(x+1)-c$, then $(\alpha+1)(\beta+1)=$

The ratio of lateral surface area to the total surface area of a cylinder with base diameter 1.6m and height 20cm is:

A month is selected at random in a year. The probability that it is March or October, is :

From your pocket money, you save $Rs. 1$ on the first day, $Rs. 2$ on the second day, $Rs. 3$ on the third day and so on. The amount of money saved by you in the month of May $2013$ is :

$\text{ABC}$ and $\text{BDE}$ are two equoilateral triangles such tha $D$ is the midpoint of $BC$. Ratio of the areas of triangles $\text{ABC}$ and $\text{BDE}$ is :

If the radius of a circle is diminished by $10\%,$ then its area is diminished by :

Each question consists of two statements, namely, Assertion $(A)$ and Reason $(R)$. For selecting the correct answer : use the following code:
Assertion $(A)$
Consider the following frequency distribution:

Class interval	$3-6$	$6-9$	$9-12$	$12-15$	$15-18$	$18-21$
Frequency	$2$	$5$	$21$	$23$	$10$	$12$

The mode of the above data is $12.4.$
Reason $(R)$
The value of the variable which occurs most often is the mode.

The value of k for which the system of linear equations x + 2y = 3, 5x + ky + 7 = 0 is inconsistent is: