Aptitude - Surds and Indices - Discussion
Discussion Forum : Surds and Indices - General Questions (Q.No. 15)
15.
| If x = 3 + 22, then the value of |  |
x | - | 1 |  |
is: |
| x |
Answer: Option
Explanation:
|
x | - | 1 | |
2 | = x + | 1 | - 2 |
| x | x |
| = (3 + 22) + | 1 | - 2 |
| (3 + 22) |
| = (3 + 22) + | 1 | x | (3 - 22) | - 2 |
| (3 + 22) | (3 - 22) |
= (3 + 22) + (3 - 22) - 2
= 4.
 |
|
x | - | 1 | |
= 2. |
| x |
Discussion:
48 comments Page 2 of 5.
Priyanka said:
9 years ago
Not getting this, can anyone explain clearly?
Bishal Dey said:
8 years ago
= 3+2√2 + 1/3+2√2 -2,
= 3+2√2 + 3 - 2√2 -2,
=6-2.
=4.
=√4=2.
= 3+2√2 + 3 - 2√2 -2,
=6-2.
=4.
=√4=2.
Akashdeep Singh said:
8 years ago
In the last stage where we find the value of [(underoot)x - 1/(underoot)x]^2 = 4.
So if you remove the square then it will become (underoot)4 i.e. 2.
(underoot)x - 1/(underoot)x = (underoot)4.
(underoot)x - 1/(underoot)x = 2.
So if you remove the square then it will become (underoot)4 i.e. 2.
(underoot)x - 1/(underoot)x = (underoot)4.
(underoot)x - 1/(underoot)x = 2.
Valens said:
9 years ago
How 4 = 2 at last?
Harshini said:
9 years ago
In the 4th step, if you see the denominator: (a+b) (a-b) = (a^2-b^2) (using the formula).
It becomes 3^2 -(2 root 2)^2.
Which is 9 - (4 * 2),
=> 9 - 8 = 1.
It becomes 3^2 -(2 root 2)^2.
Which is 9 - (4 * 2),
=> 9 - 8 = 1.
Mohan said:
6 years ago
@Joe.
In the first step, it is in the form of (a-b) ^2 formula.
In the first step, it is in the form of (a-b) ^2 formula.
Raja raviteja said:
9 years ago
^2 = 1.414.
3 + 2^2 = 5.828. Where ^x = ^5.818 = 2.414.
So, ^x - 1/^x = 2.414 - (1/2.414) = 2 =>answer.
3 + 2^2 = 5.828. Where ^x = ^5.818 = 2.414.
So, ^x - 1/^x = 2.414 - (1/2.414) = 2 =>answer.
Harigovind C B said:
8 years ago
if a÷b=4÷5 and b÷c=15÷16 , then (c^2-a^2)÷c^2+a^2 is equal to?
Can anyone solve this?
Can anyone solve this?
Mahima said:
8 years ago
4th step how to solve the denominator (3+2√2)(3-2√2)? Please explain.
BFC said:
7 years ago
How to solve 4th step the denominator (3+2√2) (3-2√2)? Please explain.
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