find one zero of (a^2 +a) x^2 +13x+6a is reciprocal of other then find value of a
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Answered by
2
The given polynomial is
(a^2 + a) x^2 + 13x + 6a
Let, the two roots are A and 1/A.
Then,
A + 1/A = -13/(a^2 + a) ...(i)
and
A × 1/A = 6a/(a^2 + a)
or, 1 = 6a/(a^2 + a)
or, a^2 + a = 6a
or, a^2 + a - 5a = 0
or, a^2 - 4a = 0
or, a (a - 4) = 0
or, a - 4 = 0, since a in not zero
or, a = 4
Therefore, the value of a is 4.
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Why not a = 0?
If a = 0 is possible. Then putting the value a = 0, we get
(0^2 + 0) x^2 + 13x + (6 × 0)
= 0 + 13x + 0
= 13x and we are not getting any quadratic polynomial.
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Answered by
1
Heya !!!!
Let one zero is Alpha .
Other zero will be 1/ Alpha
P(X) = ( A²+A)X² + 13X + 6A
This equation is of the form of AX²+BX + C = 0
Where,
A = ( A²+A) , B = 13 and C = 6A
Product of zeroes = C/A
Alpha × 1/ Alpha = 6A/ ( A²+A)
1 = 6A / (A²+A)
(A²+A) = 6A
A² = 6A - A
A² = 5A
A × A = 5A
A = 5A/A
A = 5.
HOPE IT WILL HELP YOU....... :-)
Let one zero is Alpha .
Other zero will be 1/ Alpha
P(X) = ( A²+A)X² + 13X + 6A
This equation is of the form of AX²+BX + C = 0
Where,
A = ( A²+A) , B = 13 and C = 6A
Product of zeroes = C/A
Alpha × 1/ Alpha = 6A/ ( A²+A)
1 = 6A / (A²+A)
(A²+A) = 6A
A² = 6A - A
A² = 5A
A × A = 5A
A = 5A/A
A = 5.
HOPE IT WILL HELP YOU....... :-)
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