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 5 of 5.
Kapil said:
1 decade ago
Use:
x^2+y^2 = (x+y)^2 - 2xy.
x^2+y^2 = (x+y)^2 - 2xy.
Vipin Kumar said:
1 decade ago
How came x = 2+3 and y = 2-3?
Priya said:
1 decade ago
How did we get 2(4+3) ???
Deepak Gehlot said:
9 years ago
This is wrong solution.
Jagu said:
1 decade ago
How did we get 2(4+3) ?
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