If a and b are zeroes of 4x^2-x-4 find quadratic polynomial whose zeroes are 1/2a and 1/2b
Answers
Step-by-step explanation:
Hi friend !
p(x) = 4x² - x - 4
a = 4 , b = -1 , c = -4
α and β are zeros of p(x)
we know that ,
sum of zeros = -b/a
that is ,
α + β = -b/a = 1/4
product of zeros = c/a
that is ,
αβ = -4/4 = -1
==========================
1/2α and 1/2β are zeros of a polynomial
sum of zeros = 1/2α + 1/2β
= 2α + 2β / 4αβ
= 2 [α + β] / 4αβ
= [2 × 1/4] / 4× - 1
= (1/2)/ -4
= -1/8
product of zeros =( 1/2α )( 1/2β)
= 1/4αβ
= 1/4×-1
= -1/4
a quadratic polynomial is given by ,
k {x² - [ sum of zeros ]x + [ product of zeros ]}
Answer:
to solve this lets divide the quadratic equation by 4 such that we have it in the form x
2 +(α+β)x+ab
so after dividing by 4 we have
4x² +4x+1
_________
4
x² +x+ 1
___
4
So we have α+β=1
and αb = 1
___
4
So if zeroes to the new quadratic equation are 2α and 2β, then
2α+2β=2(α+β)
=2(1)=2
and,
2α×2β=4αβ
=4× 1
___= 1
4
So the new quadratic equation with its roots 2αand2β will be
x² +(2α+2β)x+2α×2β
Putting the values, the equation would be,
x² +2x+1
Hope it helps you