QUADRATIC

ANS : C (RATIONAL).....

10 Answers

62
Lokesh Verma ·

(1-x2k)/(1-x2) x (1-x)/(1-xk)

=(1+xk)/(1+x)

Now for the above to be a polynomial, k has to be odd and positive

so both p and q are positive odd numbers...

now can u make mroe sense of the solution?

62
Lokesh Verma ·

that can be done by finding D

You will have to make some conclusion about the value D when P and Q are odd.

1
Philip Calvert ·

D = p2-60q

well !!

anyway how did u get (1-x2k)/(1-x2) x (1-x)/(1-xk)
forgive if stupid question

9
Celestine preetham ·

hint only

k is odd for the func to be polynomial

try to derive that

after that take x of form r/t sub in eq and disprove that their sum cant be even ie 0

surely has to be a fiitjee q am i right

9
Celestine preetham ·

ah by the time i typed nish had already posted wat i had in mind

62
Lokesh Verma ·

@philip that is by the sum of a geometric progression divided by another sum...

@tapan...

P is 2m+1 and Q is also 2n+1

you have taken it as even.. when it should be odd..

do

D2= p2-4.3.5q

D is odd because p is odd

difference in the squares of 2 odd numbers is 8k if i remember properly...

here the difference is only a multiple of 4 not 8.. hence D cannot be a perfect square..

Hence It cannot be rational..

62
Lokesh Verma ·

@celestine.. sorry for taking ti from you :)

21
tapanmast Vora ·

BINGO CELE!!!!

U ROCK IN BOTH MATHS N GUESSING INSTITUTES........ LOL.......

I'LL WORK OUT FRM DA HINT U GAVE.....

EARLIER I WAS TAKIN K AS EVEN SO CUDNT GET NETHING.......

9
Celestine preetham ·

tapan uv taken p,q even ??

21
tapanmast Vora ·

THANK YOU SIR!!!!!!!

GOT DA ANS!!!! :)

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