216k views
3 votes
if alpha and beta are the zeros of quadratic polynomial x square - 2, find the value of alpha cube - beta cube

User Jens Nyman
by
8.3k points

1 Answer

6 votes

Final answer:

The value of alpha3 - beta3 for the zeros of the quadratic polynomial x2 - 2 is 0, as alpha and beta are opposites and cancel out when applying the difference of cubes formula.

Step-by-step explanation:

If alpha and beta are the zeros of the quadratic polynomial x2 - 2, we are asked to find the value of alpha3 - beta3. First, let us find the roots using the quadratic formula, which for a polynomial ax2 + bx + c = 0, is given by x = (-b ± √(b2 - 4ac)) / (2a). In this case, a = 1 and c = -2, while b = 0 since the term with x is missing.

This yields the roots alpha and beta as √2 and -√2. We then substitute these values into alpha3 - beta3 and simplify using the difference of cubes formula, which is a3 - b3 = (a - b)(a2 + ab + b2). Substituting alpha for a and beta for b, we get (alpha - beta)((alpha)2 + (alpha)(beta) + (beta)2).

From the equation, we can deduce that alpha + beta = -1. Now, we can use this information to find alpha^3 - beta^3.

Using the identity for the difference of cubes, alpha^3 - beta^3 = (alpha - beta)(alpha^2 + alpha * beta + beta^2).

Substituting the values we have, we get alpha^3 - beta^3 = (-1)(alpha^2 + alpha * beta + beta^2).

Simplifying further, we find the value of alpha3 - beta3 equals 0, because alpha and beta are opposites and cancel each other out.

User Adil Bhatty
by
7.6k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories