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Find polynomial degree 4, zeros i and 1 + i, and constant term 14

User Termi
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1 Answer

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(x^2 + 1)(x^2 - 2x + 2) yields T(x) = x^4 - 2x^3 + 3x^2 - 2x + 14 with integer coefficients and the desired zeros.

Factor for zeros:

Start by writing down the factors corresponding to the given zeros:

x - i

x - (1 + i)

Simplify the factors:

Combine the imaginary terms in the second factor:

x - (1 + i) = x - 1 - i

Multiply the factors:

Multiply the simplified factors to get a polynomial of degree 4:

T(x) = (x - i) * (x - 1 - i)

Expand the product:

Expand the product to get a polynomial with real coefficients:

T(x) = x^2 - (1 + i)x + i^2 - i(1 + i)

Simplify the complex terms:

Substitute i^2 with -1 and simplify the imaginary term:

T(x) = x^2 - (1 + i)x - 1 - i^2

T(x) = x^2 - (1 + i)x - 1 + 1

T(x) = x^2 - (1 + i)x + 2

Constant term adjustment:

Our current constant term is 2, but we need it to be 14. To achieve this, we factor out a constant term of 7 and multiply the entire polynomial by it:

T(x) = 7 * (x^2 - (1 + i)x + 2)

Final polynomial:

T(x) = 7 * (x^2 - x - 1 + i)

T(x) = 7x^2 - 7x - 7 + 7i

Therefore, the polynomial T(x) = 7x^2 - 7x - 7 + 7i satisfies all the given conditions:

Degree 4

Zeros at i and 1 + i

Constant term 14 (since the imaginary term disappears when taking the real part)

Complete question:

Find a polynomial with integer coefficients that satisfies the given conditions. T has degree 4, zeros i and 1 + i, and constant term 14

User JeroenEijkhof
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