x − x 1 + 1 − x 1 = x
Find all the real solutions to the equation above.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Those are extraneous roots, there is a typo I think!! :p
Log in to reply
Oh! Thank you for spotting my mistake! I've corrected it.
Problem Loading...
Note Loading...
Set Loading...
Since we're dealing with radicals, let's square both sides of the equation in hopes of converting the radical equation into a polynomial equation, which is easier to solve.
By squaring the equation in question, (recall that ( a + b ) 2 = a 2 + b 2 + 2 a b ), we have
( x − x 1 ) + ( 1 − x 1 ) + 2 ( x − x 1 ) ( 1 − x 1 ) x 2 + x − 2 + 2 ( x 2 − 1 ) ( x − 1 ) ( 2 ( x 2 − 1 ) ( x − 1 ) ) 2 4 ( x 2 − 1 ) ( x − 1 ) x 6 − 2 x 5 − x 4 + 2 x 3 + x 2 ( x 3 + x 2 + x ) 2 x ( x 2 − x − 1 ) x = = = = = = = = x 2 x 3 ( x 3 − x 2 − x + 2 ) 2 ( x 3 − x 2 − x + 2 ) 2 0 0 0 0 , 2 1 ± 5 by Quadratic formula
But substituting all these three values of x into the original equation shows that x = 0 and x = 2 1 − 5 are extraneous roots (they do not satisfy the given equation). Thus the solution of x satisfying the equation in question is 2 1 + 5 .