Math, asked by SakshamBrilliantKid, 1 year ago

If f(x)=
(x - 2)( {x }^{2}  - x - a)
and g(x)=
(x + 2)( {x}^{2}  + x - b)
and their HCF is
 {x}^{2}  - 4
then find the value of (a-b) where a and b are constants.


SakshamBrilliantKid: Please help me with this question.

Answers

Answered by δΙΔΔΗλΣΓΗΛ
12
★ POLYNOMIALS AND RATIONAL EXPRESSIONS ★

f(x) = (x - 2)(x {}^{2}  - x - a) \\ g(x) = (x + 2)(x {}^{2}  + x - b) \\
H.C.F. = x² - 4 = ( x +2 ) ( x -2 )

Hence ( x + 2 ) is a factor of ( x² - x - a )

Which yields ; a = 6

Similarly for ( x - 2 )

Which gives b = 6

Hence , a - b = 6 - 6 = 0

SakshamBrilliantKid: why x+2 is a factor of (x^2-x-a) ??
δΙΔΔΗλΣΓΗΛ: Full of HCF is Highest Common Factor , and it's clearly mentioned that factor of f(x) and g(x) is x² - 4 , so , it's a factor ,
δΙΔΔΗλΣΓΗΛ: full form*
SakshamBrilliantKid: so it should also be a factor of (x-2) as in f(x)
SakshamBrilliantKid: why it's only for the second term ?
δΙΔΔΗλΣΓΗΛ: Then the HCF and polynomialic system will collapse to zero , to avoid that we pick 2nd factor
SakshamBrilliantKid: ohk
SakshamBrilliantKid: thank u
SakshamBrilliantKid: you in india
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