Solve the following equation ( x + 1 ) 2 1 − ( x − 1 ) 2 1 = 1
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Very neat. But there is no need to solve for b. You can find x from a = 3/2.
very intelligent solution.But we can calculate x from 'a' value
I saw a similar problem on aops recently. I had the same solution.
I didn't understood
lol...i keep typing 12.5......
not level four sum!!
Squaring and rearranging gives 2 x − 1 = 2 x 2 − 1 . Squaring again, canceling and rearranging gives 4 x − 5 = 0 , that is, x = 5 / 4 = 1 . 2 5 . It's easy to check that this value indeed works.
How does squaring and rearranging give 2x-1? Shouldn't it be 2x^2-2? Am I wrong???
Did in the same way!!
Impressive
First,we change the equation to x + 1 − x − 1 = 1 Then,we rearrange the terms to get x + 1 − 1 = x − 1 Squaring both sides,we get x + 1 − 2 x + 1 + 1 = x − 1 Subtracting the x from both sides,we get 2 − 2 x + 1 = − 1 Then,we get 2 x + 1 = 3 .Dividing by 2,we get x + 1 = 2 3 .Squaring both sides,we get ( x + 1 ) = 4 9 So, x = 4 5 = 1 . 2 5
Thanks :) ....
A common solution is as follows:
{ (x+1) }^{ 1/2 }=1+{ (x-1) }^{ 1/2 }
squaring both sides to the above equation,
(x+1)=1+x-1+2{(x-1)}^{1/2}
1=2{(x-1)}^{1/2}
again squaring the both sides to the above equation,
1=4(x-1)
x=5/4.
Hey yo,
(x+1)^0.5 = 1 + ( x - 1)^0.5
Squaring both sides,
1 = 2(x-1)^(0.5)
(x-1)^(0.5) = 1/2,
Squaring both sides once again,
x = 1/4 + 1 = 1.25.....(try to insert the value to check the answers)
(1.25 + 1)^(0.5) - ( 1.25 -1 )^(0.5) = 1 (yeah x = 1.25)....
thanks.....
yea same. But the soln would be better with LaTeX formatting
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A different solution is as follows:
Let a 2 = x + 1 and b 2 = x − 1 .
We see that a 2 − b 2 = 2 . Also, from the equation, a − b = 1 .
Dividing the second equation from the first we get a + b = 2 .
Adding this to the second equation and simplifying, we get a = 2 3 so b = 2 1 .
Thus x − 1 = 4 1 so x = 4 5 = 1 . 2 5 .