Solve equation using formula : 2x^2 – 3x – 1 = 0 - Vidyadip

Question

Solve equation using formula : $2x^2 – 3x – 1 = 0$

✓

Answer

$\begin{aligned} & 2 x^2-3 x-1=0 \\ & \text { Here } a=2, b=-3, c=-1 \\ & D=b^2-4 a c \\ & =(-3)^2-4 \times 2 \times(-1) \\ & =9+8 \\ & =17 \\ & \because x=\frac{-b \pm \sqrt{D}}{2 a} \\ & =\frac{-(-3) \pm \sqrt{17}}{2 \times 2} \\ & =\frac{3 \pm \sqrt{17}}{4} \\ & \therefore x=\frac{3+\sqrt{17}}{4}, \frac{3-\sqrt{17}}{4} .\end{aligned}$

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 "[2 Mark Question Answer]" from Quadratic Equations in One Variable→Quadratic Equations in One Variable — all question types→Mathematics STD 10 question papers→ICSE Board STD 10 question papers→ICSE Board question paper generator→

Similar questions

Prove the following identitie : $\sqrt{\frac{1-\cos A}{1+\cos A}}=\frac{\sin A}{1+\cos A}$

A bag contains 10 red balls, 16 white balls and 8 green balls. A ball is drawn out of the bag at random. What is the probability that the ball drawn will be : neither red nor green?

If $A =\left[\begin{array}{ll}a & b \\ c & d\end{array}\right]$ and $I =\left[\begin{array}{ll}1 & 0 \\ 0 & 1\end{array}\right]$ show that $A^2 - (a + d) A = (bc - ad) I.$

Prove that$\frac{\cot ^2 A}{\operatorname{cosec} A-1}-1=\operatorname{cosec} A$

One root of the quadratic equation $x^2+(3-2 a) x-6 a=0$ is $-3,$ find its other root.

From a deck of 52 cards, all the face cards are removed and then the remaining cards are shuffled. Now one card is drawn from the remaining deck. Find the probability that the card drawn is: a black card

The volume of a conical tent is $1232 m^3$ and the area of the base floor is $154 m^2.$ Calculate the: height of the tent.

Find the sum of first 51 terms of an AP whose second and third terms are 14 and 18 respectively.

Calculate the investment required to buy:
150 shares of Rs 100 each at a premium of 12%.

Find the mid – point of the line segment joining the point: (5, -3) and (-1, 7)