Question

If α, β, y are zeroes of cubic polynomial x3 + 5x – 2, then the value of α³ + β³ + y³ is (A) 5 (B) 4
(C) 6 (D) 3

Answer 1

ANS= (C)6

x3+ 0x2 + 5x - 2

a=1 , b=0 , c=5 , d=-2

$\alpha + \beta + \gamma = \frac{ - b}{a}$

=0

${ \alpha }^{3} + { \beta }^{3} + { \gamma }^{3} = 3 \alpha \beta \gamma$

=3 × -d/a

=3 × 2

=6

Answer 2

Answer:

Its very simple. see >

they say  it is cubic polynomial but it is of 3 terms  

you can see that   the second value is missing of x^2 which means it is 0

so we can conclude  

b= 0 &   a= 1  &c=5   &constant term is  -2

so that it

apply the formulae

α+ β+ y = -coefficient of x^2/ coff of x^3

   we get        =0

cubing both sides

we will get

α^3 +β^3+ y^3 =3 α β y { α β y=-constant term/coff x^2= 2}

then

our ans is 6  

congrats

Step-by-step explanation: