Question
In the following, determine whether the given values are solution of the given equation or not:
$\text{x}^2-\sqrt{2}\text{x}-4=0,$ $\text{x}=-\sqrt{2},$ $\text{x}=-2\sqrt{2}$

Answer

$\text{x}^2-\sqrt{2}\text{x}-4=0,$ $\text{x}=-\sqrt{2},$ $\text{x}=-2\sqrt{2}$When, $\text{x}=-\sqrt{2}$
Substituting $\text{x}=-\sqrt{2}$
L.H.S.
$=\text{x}^2-\sqrt{2}\text{x}-4$
$=(-\sqrt{2})^2-\sqrt{2}(-\sqrt{2})-4$
$=2+2-4=0$
= R.H.S.
$\therefore\text{x}=-\sqrt{2}$ is its solution
When, $\text{x}=-2\sqrt{2}$
Substituting $\text{x}=-2\sqrt{2}$
L.H.S.
$=\text{x}^2-\sqrt{2}\text{x}-4$
$=(-2\sqrt{2})^2-\sqrt{2}(-2\sqrt{2})-4$
$=8+4-4$
$=8\neq\text{R.H.S}$
$\therefore\text{x}=-2\sqrt{2}$ is not its solution.

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

Similar questions

A bucket is in the form of a frustum of a cone. its depth is 15cm and the diameters of the top and the bottom are 56cm and 42cm, respectively. Find how many litres of water can the bucket hold. $\Big[\text{Take}\ \pi=\frac{22}{7}.\Big]$
Prove the following trigonometric identities.
$\frac{\tan^2\text{A}}{1+\tan^2\text{A}}+\frac{\cot^2\text{A}}{1+\cot^2\text{A}}=1$
The distance between Mumbai and Pune is $192\ km$. Travelling by the Deccan Queen, it takes $48$ minutes less than another train. Calculate the speed of the Deccan Queen if the speed of the two trains differ by $20\ km/hr$.
The following is the frequency distribution of blood pressure measured for 100 patients.
Blood pressure
in suitable units.
110-115115-120120-125125-130130-135
No. of patients2355283
Find the modal Blood pressure of the patient.
A piggy bank contains hundred 50 paise coins, fifity ₹1 coins, twenty ₹2 coins and ten ₹5 coins. If it is equally likely that one of the coins will fall out when the bank is turned upside down, find the probability that the coin which fell:
  1. Will be a 50 paise coin.
  2. Will be of value more than ₹1.
  3. Will be of value less than ₹5.
  4. Will be a ₹1 or ₹2 coin.
Draw the graph of the equations x = 3, x = 5 and 2x - y - 4 = 0. Also, find the area of the quadrilateral formed by the lines and the x-axis.
Find the mean, marks per stufdent, using assumed-mean method:
Marks
$0-10$
$10-20$
$20-30$
$30-40$
$40-50$
$50-60$
Number of students
$12$
$18$
$27$
$20$
$17$
$6$
A right circular cylinder and aright circular cone have equal bases and equal heights. If their curved surfaces are in the ratio 8 : 5, determine the ratio of the radius of the base to the height of either of them.
In the given figure, $\triangle\text{ABC}$ and $\triangle\text{DBC}$ have the same base BC. If AD and BC intersect at O, prove that $\frac{\text{ar}(\triangle\text{ABC})}{\text{ar}(\triangle\text{DBC})}=\frac{\text{AO}}{\text{DO}}.$
Given : In $\triangle \mathrm{ABC}$, bisector of $\angle \mathrm{C}$ interesects seg $A B$ in the point $E$.To prove : $\frac{\mathrm{AE}}{\mathrm{EB}}=\frac{\mathrm{CA}}{\mathrm{CB}}$