Q Find the quadratic polynomial, the sum and product of whose zeroes are 4 and 1, respectively.
Answers
Answer:
Step-by-step explanation:
We know that ,
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Equation of the polynomial whose
zeroes are p and q is
k(x^2 - ( p + q ) x + pq )
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According to the given problem,
Sum of the zeroes = -1
p + q = - 1 -----( 1 )
Product of the zeroes = - 20
pq = - 20 -----( 2 )
Therefore , required polynomial is
k [ x^2 - ( - 1 ) x + ( -20 )
= k ( x^2 + x - 20)
k is real number ,
Let us assume k = 1,
x^2 + x - 20
ii) Finding zeroes ,
( p - q )^2 = ( p + q )^2 - 4pq
= ( -1 )^2 - 4 ( -20 )
[ from ( 1 ) and ( 2 ) ]
= 1 + 80
= 81
Therefore ,
p - q = + or - 9 -----( 3 )
Add ( 1 ) and ( 3 )
We get p = -5 or 4
Put p values in ( 2 ), we get
q = 4 or -5
If p = - 5 then q = 4
Or
If p = 4 then q = -5
I hope this helps you.
hey matw:
given here
sum if zeroes = 4
and ,
product of zeroes = 1
quadratic equation
x^2-(sum of zeroes )x + (products of zeroes)= 0
so,
x^2 - (4)x+1=0.
i hopes its helps u.
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@abhi.