Aptitude - Square Root and Cube Root - Discussion

Two answers are possible here.

One is: 2a-1 and 1-2a because the square of both numbers are the same.

Anyone, please clear this.

@All.

We can take positive or negative square root that is (2a-1) or -(2a-1) => (1-2a) but according to the given option we need a positive value if we consider the value (2a-1) then the answer will be negative.

=> (2a-1)+3a.
=> 5a-1,
=>5*0.1039-1,
=>0.5195-1,
=>-0.4855.

but if we put the value (1-2a) then the calculation will be;
=>(1-2a)+3a.
=>1+a,
=>1+0.1039,
=>1.1039.

2a<1 so use (1-2a)^2.

But (2a-1)^2 is a imaginary number.

Guys..this will make you understand,
Its 4a^2 * 4a+1... i.e a * 2ab+b^2.where a=2a...(4a^2) and b=1...
So, we got formula of (a-b)^2..removing root..i.e (a-b).

We get,
(2a-1)+3.
(2 * 0.1039- 1) + 3(0.1039).
(0.2078-1) + 0.3117.
0.7922 + 0.31 17.
1.1039.

Why w (1-2a) ^2, whekat ey not (2a-1) ^2?

Please tell me.

Any anyone explain this clearly.

Yes, @Varsha Jadhav.

The actual answer is -0.4805.

@Krishna.

But, my factor is (2a-1)(2a-1).

Than 2a-1+3a,
=5a-1,
=5*0.1039-1.
=0.5195-1=-0.4805.

I have one doubt about the solution to the problem why should we take 1-2*a only, there is another chance to take equation as 2*a-1 please tell me a solution.

Guys let me explain this things.
Everyone discuss here is (a-b)^2.

Actually (a-b)^2= (b-a)^2.
For example (5-2)^2=(2-5)^2. Cause square of a negative no is positive.

But you guys know what's wrong in here. The wrong is square root of a no is either positive or negative. In solution taking square root come with +(1-2a) and -(1-2a) so while considering these two we get two answer.

Both of them will satisfy the condition. Hope you guys are get it. Here solution consider only one possibilities of answer.