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.
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?
Ram said:
8 years ago
(2 + 3) 2 + (2 - 3) 2.
Explanation:
7+4root3+3+4-root3+3.
+4root3-4root3 cancel.
After that,
4+3+4+3 = 14.
Explanation:
7+4root3+3+4-root3+3.
+4root3-4root3 cancel.
After that,
4+3+4+3 = 14.
Naren said:
8 years ago
Here, 2(x^2+y^2) = (x+y)^2+(x+y)^2.
Jagu said:
1 decade ago
How did we get 2(4+3) ?
Gaurav said:
1 decade ago
Asnwer to this seems to be '-10'.
Tank Mayur B. said:
1 decade ago
This is wrong solution .
because: ((a+b)/(a-b))*((a+b)/(a+b))=(a+b)2/(a2 + b2)
because: ((a+b)/(a-b))*((a+b)/(a+b))=(a+b)2/(a2 + b2)
M.V.KRISHNA/PALVONCHA said:
1 decade ago
Hello gaurav and tank mayur.
This is the process of rationalization.
The denominator is multiplied and divided to selected value.
Hope you understand.
This is the process of rationalization.
The denominator is multiplied and divided to selected value.
Hope you understand.
Mayur said:
1 decade ago
Hello M.V.Krishna
You are absolutely right
Thank you....
You are absolutely right
Thank you....
Yogendra said:
1 decade ago
This can also be solvein this formula: (A+B)2 =(a+b)2-2ab
Raje said:
1 decade ago
Its called conjugate . + in denominoter means u have to multiply & divide the same number but put - sign. denominoter - sign means put + vice versa.
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