If x>0, then 1/[v(2x)+vx]=
A. 1/v(3x)
B. 1/[2v(2x)]
c. 1/(xv2)
D. (v2-1)/vx
E. (1+v2)/vx
A clear cut answer is A. However the Questions answer is D (as per the Question Paper). Kindly let me know if I am missing anything.
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In the posted problem, v = √.
Here is the problem with the intended notation:
(√x + √y)(√x - √y) = x-y.
Thus:
1 / [√(2x) + √x]
= 1 / (√x)(√2+1)
= (1)(√2-1) / (√x)(√2+1)(√2-1)
= (√2-1) / (√x)(2-1)
= (√2-1) / √x
The correct answer is D.
Here is the problem with the intended notation:
Note the following:If x>0, then 1 / [√(2x) + √x] =
A. 1 / √(3x)
B. 1/ 2√(2x)
c. 1 / x√2
D. (√2-1) / √x
E. (1+√2) / √x
(√x + √y)(√x - √y) = x-y.
Thus:
1 / [√(2x) + √x]
= 1 / (√x)(√2+1)
= (1)(√2-1) / (√x)(√2+1)(√2-1)
= (√2-1) / (√x)(2-1)
= (√2-1) / √x
The correct answer is D.
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As a tutor, I don't simply teach you how I would approach problems.
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Quote:
If x>0, then 1 / [√(2x) + √x] =
A. 1 / √(3x)
B. 1/ 2√(2x)
c. 1 / x√2
D. (√2-1) / √x
E. (1+√2) / √x
Solution:
in such problems where you find problem in solving algebra try following method:
Let x=1; in such case it should match the equation and we all know √3= 1.732; √2 = 1.414 and √1 = 1
replacing x=1 in question it becomes:
1 / 1.414 + 1
= 1 / 2.414
= .414 ..... (1)
may take some time according to your caculation speed and the squence of options you pick to start replacing 'x', but will surely helps you to attempt the question and get the right Ans.
option (D)
√2 -1 / √x
= 1.414 - 1 / √1 ; as x=1
= .414
Ans is 'D'
If x>0, then 1 / [√(2x) + √x] =
A. 1 / √(3x)
B. 1/ 2√(2x)
c. 1 / x√2
D. (√2-1) / √x
E. (1+√2) / √x
Solution:
in such problems where you find problem in solving algebra try following method:
Let x=1; in such case it should match the equation and we all know √3= 1.732; √2 = 1.414 and √1 = 1
replacing x=1 in question it becomes:
1 / 1.414 + 1
= 1 / 2.414
= .414 ..... (1)
may take some time according to your caculation speed and the squence of options you pick to start replacing 'x', but will surely helps you to attempt the question and get the right Ans.
option (D)
√2 -1 / √x
= 1.414 - 1 / √1 ; as x=1
= .414
Ans is 'D'
