If alpha and beta are the zeros of the polynomial p(x)=x^2+x+1 then find the value of 1÷alpha+1÷beta 2)alpha^2+beta^2

User Icon for Reiny Reiny answered
10 years ago

I will use a for alpha and b for beta

then from the properties of zeros of a quadratic
a+b = -1
ab = 1

then 1/a + 1/b
= (b+a)/(ab) = -1/1 = -1

a^2 + b^2
= (a+b)^2 - 2ab
= (-1)^2 - 2(1)
= 1 - 2 = -1

User Icon for Diya K Vineeth Diya K Vineeth answered
4 years ago

Thank you very much

User Icon for Sunami Sunami answered
3 years ago

You all r wrong

User Icon for Abhinav Abhinav answered
3 years ago

Answer

Given polynomial is x2−a(x+1)−b=0
x
2
−ax−a−b=0
x
2
−ax−(a+b)=0

α+β=a,αβ=−a−b.......... given
(α+1)(β+1)=αβ+α+β+1
=αβ+(α+β)+1
=−a−b+a+1=0⇒b=1

User Icon for Clown Bot Clown Bot answered
1 year ago

1) Well, if alpha and beta are the zeros of the polynomial, that means that plugging alpha or beta into the polynomial will give us 0. So let's try that:

p(alpha) = alpha^2 + alpha + 1 = 0
p(beta) = beta^2 + beta + 1 = 0

Now, let's find 1/alpha + 1/beta:
1/alpha + 1/beta = (alpha + beta) / (alpha * beta)

Hm, seems like we need to find alpha + beta and alpha * beta.

Let's use Vieta's formulas:
alpha + beta = -1
alpha * beta = 1

Plugging these values into the equation:

1/alpha + 1/beta = (-1) / 1
1/alpha + 1/beta = -1

So, the value of 1/alpha + 1/beta is -1.

2) Let's find alpha^2 + beta^2:

alpha^2 + beta^2 = (alpha + beta)^2 - 2alpha*beta

Using Vieta's formulas, we can find:
alpha + beta = -1
alpha * beta = 1

Plugging these values in:

alpha^2 + beta^2 = (-1)^2 - 2(1)
alpha^2 + beta^2 = 1 - 2
alpha^2 + beta^2 = -1

So, the value of alpha^2 + beta^2 is -1.

User Icon for Explain Bot Explain Bot answered
1 year ago

To find the value of 1/alpha + 1/beta, we need to know the values of alpha and beta.

Given that alpha and beta are the zeros of the polynomial p(x) = x^2 + x + 1, we can use the fact that the sum of the roots of a quadratic polynomial is equal to the coefficient of the linear term (x) with the opposite sign.

In this case, the sum of the roots (alpha + beta) will be equal to the coefficient of x, which is 1. So, we have alpha + beta = -1.

Next, we want to find the product of the roots (alpha * beta). For a quadratic polynomial, the product of the roots is equal to the constant term divided by the coefficient of the quadratic term (x^2).

In this case, the constant term is 1 and the coefficient of the quadratic term is 1, so the product of the roots (alpha * beta) = 1/1 = 1.

Now, we can find the value of 1/alpha + 1/beta.
Using the formula for the sum of fractions, we can rewrite it as (beta + alpha) / (alpha * beta).

Plugging in the values we found earlier, we have (-1) / (1) = -1.

Therefore, the value of 1/alpha + 1/beta is -1.

To find the value of alpha^2 + beta^2, we can use the identity (alpha + beta)^2 - 2(alpha * beta).

Plugging in the values we found earlier, we have (-1)^2 - 2(1) = 1 - 2 = -1.

Therefore, the value of alpha^2 + beta^2 is -1.