Math Problem Statement

The polynomial x^3 + px^2 - x - 2, p ∈ ℝ, has x - 1 as a factor. What is the value of p?

Solution

The problem states:

"The polynomial x3+px2x2x^3 + px^2 - x - 2, with pRp \in \mathbb{R}, has x1x - 1 as a factor. What is the value of pp?"

Solution:

If x1x - 1 is a factor of the polynomial, then x=1x = 1 is a root of the polynomial. That means substituting x=1x = 1 into the polynomial should give us zero.

The polynomial is: f(x)=x3+px2x2f(x) = x^3 + px^2 - x - 2

Substitute x=1x = 1 into this expression: f(1)=(1)3+p(1)2(1)2f(1) = (1)^3 + p(1)^2 - (1) - 2 f(1)=1+p12=0f(1) = 1 + p - 1 - 2 = 0 Simplifying: p2=0p - 2 = 0 p=2p = 2

Therefore, the value of pp is 2\boxed{2}.


Would you like more details or have any questions?

Here are 5 related questions to expand on this topic:

  1. How do you factorize a cubic polynomial when one root is known?
  2. What other techniques can be used to find the roots of a cubic polynomial?
  3. How can the remainder theorem be applied to check if a factor divides a polynomial?
  4. What does it mean when a polynomial has multiple roots?
  5. How does synthetic division help in dividing polynomials by linear factors?

Tip: When testing if xrx - r is a factor of a polynomial, substitute rr into the polynomial. If the result is zero, xrx - r is indeed a factor.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Polynomials
Roots and Factors

Formulas

Factor Theorem: If (x - r) is a factor of a polynomial, then f(r) = 0.

Theorems

Factor Theorem
Remainder Theorem

Suitable Grade Level

Grades 10-12