52448311
The polynomial expression is \(T(x) = x^3 - 2x^2 + x - 2\).
a) Verify algebraically that \(x = 2\) is a zero.
b) Factor \(T(x)\) as a product of one linear factor and one quadratic factor.
c) Explain why the quadratic factor cannot be factored further into real linear factors.
Hints
- Substitute the proposed zero into the expression.
- Group the first two terms and the last two terms to reveal a common binomial factor.
- Consider whether any real number has a square equal to \(-1\).
Solution
1. Substitute \(x = 2\): \(T(2) = 2^3 - 2(2^2) + 2 - 2 = 8 - 8 + 2 - 2 = 0\). Therefore, \(x = 2\) is a zero.
2. Factor by grouping: \(x^3 - 2x^2 + x - 2 = x^2(x - 2) + 1(x - 2)\).
3. Factor out \(x - 2\): \(T(x) = (x - 2)(x^2 + 1)\).
4. The equation \(x^2 + 1 = 0\) would require \(x^2 = -1\), which has no real solution. Therefore, \(x^2 + 1\) has no real linear factors.
Answer
a) \(T(2) = 0\)
b) \(T(x) = (x - 2)(x^2 + 1)\)
c) \(x^2 + 1 > 0\) for every real \(x\), so it has no real zeros and no real linear factors.
