Aptitude - Square Root and Cube Root - Discussion
Discussion Forum : Square Root and Cube Root - General Questions (Q.No. 7)
7.
| If x = | 3 + 1 | and y = | 3 - 1 | , then the value of (x2 + y2) is: |
| 3 - 1 | 3 + 1 |
Answer: Option
Explanation:
| x = | (3 + 1) | x | (3 + 1) | = | (3 + 1)2 | = | 3 + 1 + 23 | = 2 + 3. |
| (3 - 1) | (3 + 1) | (3 - 1) | 2 |
| y = | (3 - 1) | x | (3 - 1) | = | (3 - 1)2 | = | 3 + 1 - 23 | = 2 - 3. |
| (3 + 1) | (3 - 1) | (3 - 1) | 2 |
x2 + y2 = (2 + 3)2 + (2 - 3)2
= 2(4 + 3)
= 14
Discussion:
45 comments Page 3 of 5.
Pavan Kumar said:
2 years ago
The value of √3 is 1.732. By applying this, we will get the answer.
(5)
Rajnish Jais said:
1 decade ago
Since (x+y)^2-2xy = x^2+y^2.
x+y = 4, 2xy = 1.
Therefore, x^2+y^2 = 14.
x+y = 4, 2xy = 1.
Therefore, x^2+y^2 = 14.
Nithin said:
1 decade ago
(a+b)2 + (a-b)2 = 2(a2 + b2)
Abhinav said:
1 decade ago
What if we keep the value of root 3 and proceed? the answer will be 10.
Abhirup said:
10 years ago
The answer to this question is correct. They have just step-jumped.
Kalesha said:
9 years ago
(2 + 3) 2 + (2 - 3) 2.
2 (4 + 3).
How can anyone explain this?
2 (4 + 3).
How can anyone explain this?
Sinku said:
8 years ago
x2+y2=(x-y)2+2xy, can we use this formula?
Anyone explain me.
Anyone explain me.
(1)
Shyam said:
1 decade ago
Rationalizing the denominator. Makes it very easy and find xy.
Yogendra said:
1 decade ago
This can also be solvein this formula: (A+B)2 =(a+b)2-2ab
Mayur said:
1 decade ago
Hello M.V.Krishna
You are absolutely right
Thank you....
You are absolutely right
Thank you....
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