Aptitude - Square Root and Cube Root - Discussion
Discussion Forum : Square Root and Cube Root - General Questions (Q.No. 6)
6.
If a = 0.1039, then the value of 4a2 - 4a + 1 + 3a is:
Answer: Option
Explanation:
4a2 - 4a + 1 + 3a = (1)2 + (2a)2 - 2 x 1 x 2a + 3a
= (1 - 2a)2 + 3a
= (1 - 2a) + 3a
= (1 + a)
= (1 + 0.1039)
= 1.1039
Discussion:
71 comments Page 5 of 8.
Barjinder singh said:
1 decade ago
Is there any other method to solve it?
Sujith said:
1 decade ago
We can use both (2a-1), (1-2a). Its just based on options they given.
Shubham bansal said:
1 decade ago
Ok here we could check options but think if in any test both the answers are given then with which we have to go with.
Ashit patel said:
1 decade ago
2a-1=1-2a?
Vishal said:
10 years ago
Since the value of a has been given in the question hence 2a-1 can't be square root since then the square root will be negative and options given as answers are positive. Hope you guys got it.
Siddharth said:
10 years ago
Both (1-2a)^2 and (2a-1)^2 are correct we need to see from the options which answer is available.
Phani said:
10 years ago
Why should we take (1-2a) and the given is 4a^2 -4a+1 we can also take 2a-1.
Gupta said:
10 years ago
How is it 1-2a? It should be 2a-1.
Renga said:
9 years ago
2a - 1 + 3a = 5a - 1.
= 5(0.1039) - 1 = -0.4805.
Can you please explain, what is (1 - 2a)?
= 5(0.1039) - 1 = -0.4805.
Can you please explain, what is (1 - 2a)?
Zareena said:
9 years ago
(1 - 2a)2 is wrong because if you expand it give 4a^2 + 4a + 1 which is not matching with the question.
So, - 0.4805 is the right answer.
So, - 0.4805 is the right answer.
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