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 4 of 8.
G Anirudh said:
8 years ago
Let me help you guys.
Here the given question can have 2 different answers as;
(1-2a)^2 = 4a^2-4a+1= (2a-1)^2.
Hence for questions like these, try to verify with both the answers and select the given option.
here answers are -0.4805 and 1.1039. so since all options are +ve we select the +ve ans i.e. 1.1039.
Here the given question can have 2 different answers as;
(1-2a)^2 = 4a^2-4a+1= (2a-1)^2.
Hence for questions like these, try to verify with both the answers and select the given option.
here answers are -0.4805 and 1.1039. so since all options are +ve we select the +ve ans i.e. 1.1039.
Amitabha Das said:
8 years ago
It can also be (2a-1)^2.
Maurya said:
8 years ago
Since all the options are positive we have to choose (1-2a).
Shrikant T. said:
8 years ago
Here you have given the formula (x-y)^2.
If we take the value of x = 2a and value of b = 1 then,
(x-y)^2 = x^2 -2xy + y^2.
i.e 4a^2 - 4a + 1.
But here you have taken (1-2a)^2, which yields the completely different equation.
Please correct and clarify.
If we take the value of x = 2a and value of b = 1 then,
(x-y)^2 = x^2 -2xy + y^2.
i.e 4a^2 - 4a + 1.
But here you have taken (1-2a)^2, which yields the completely different equation.
Please correct and clarify.
Surya said:
7 years ago
Why not 2a-1?
How can 1-2a?
How can 1-2a?
Siri said:
5 years ago
I am not understanding this whole solution, can someone explain to me in an easy manner?
Rahul said:
1 decade ago
+*- = -
Then how it bcmz (1-2a)+3a = 1+a ?
Anyone can tell?
Then how it bcmz (1-2a)+3a = 1+a ?
Anyone can tell?
Joginder said:
1 decade ago
I have the same doubt, why cant it be (2a-1)2.
Sid said:
1 decade ago
Who goes for the answer anyone solving this would go for the formula asq - 2ab + bsq which will give (2a - 1)sq.
I don't think (1-2a)sq can be the way out.
I don't think (1-2a)sq can be the way out.
Mannoj kumar said:
1 decade ago
I agree with sayani. We need to see the options also.
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