Flag Algebra> Inequalities...
question mark

The value of x satisfying (x+1)/(x-1) + (x-2)/(x+2)+(x-3)/(x+3)+(x+4)/(x-4)=4 are(a)(-5+3451/2)/10(b) (5+3401/2)/8(c)(-5+3251/2)/16(d)none

Vaibhav Mathur , 15 Years ago
Grade 12
anser 1 Answers
AskIITians Expert Hari Shankar IITD

Last Activity: 15 Years ago

Hi

The given equation is

(x+1)/(x-1) + (x-2)/(x+2)+(x-3)/(x+3)+(x+4)/(x-4)=4

Write (x+1) as (x-1)+2. So the first term becomes

1+ 2/(x-1).

Similarly, the second term becomes 1 + 2/(x-2), and so on.

Do this to all four terms on the LHS. Now the equation becomes

1+ 2/(x-1) + 1+ 2/(x-2) + 1+ 2/(x-3) + 1+ 2/(x-4) = 4

or, 4 + 2/(x-1) + 2/(x-1) + 2/(x-1) + 2/(x-1) = 4

or, 2 ( 1/(x-1) + 1/(x-2) + 1/(x-3) + 1/(x-4)) = 0

or, 1/(x-1) + 1/(x-4) + 1/(x-3) + 1/(x-2) = 0

or,

[(x-4)+(x-1)]/[x2-5x+4] + [(x-3)+(x-2)]/[x2-5x+6] = 0

or,

(2x-5)/[x2-5x+4] = -(2x-5)/[x2-5x+6]

Therefore Either 2x-5 = 0 or 1/[x2-5x+4] = -1/[x2-5x+6]

x = 5/2 or [x2-5x+6]=-[x2-5x+4]

x=5/2 or 2x2-10x+10=0

x=5/2 or x2-5x+5=0

x=5/2 or x = (5+root(5))/2

These are the only solutions. I think there is some typing error in the options but I am sure these 3 are the only solution. I have verified it using MATLAB software also.

 

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...