Discussions
Select Date
Tags:

This topic is not avialable

SIDDHARTHSHANKAR

· started a discussion

· 1 Months ago

Respected admin;

Here (x + 1/x) = 5/2 & 3/2 after solving quadratic equation. How can expression (x + 1/x) be less than 2 for any value of x???

So in my opinion it should be 5/2 ...

Please correct me in case I am wrong .....

Question:

If  x2+ 1x2    − 4  x+ 1x    +  234    = 0. Find  x+ 1x.   

Options:
A)

5/2

B)

3/2 

C)

Both (a) and (b) 

D)

None of these

Solution:

Ans: (c)  x2+ 1x2    − 4  x+ 1x    +  234    = 0

x2+ 1x2+ 2    − 4  x+ 1x    +  234     − 2= 0

x+ 1x2    − 4  x+ 1x    +  154     = 0

Let   x+ 1x    = k

K2 – 4k +  154     = 0

4K2 – 16k + 15 = 0

(2k – 5)(2k – 3) = 0

K = 5/2, 3/2

For Video Solution Click on the link given below:

Knowledge Expert

· commented

· 1 Months ago

Dear Student,
No where in the question given that x is an integer, it also can be fraction, So go through the answer marked.
Keep Learning with Us
Best Wishes
Team Toprankers

All Rights Reserved Top Rankers