Web Analytics

Questions › Math

Math Asked by a SnapAndSolve user · about 2 hours ago

Write a polynomial function of least degree that has rational coefficients, a leading coefficient of 1, and...

5. Write a polynomial function of least degree that has rational coefficients, a leading coefficient of 1, and the zeros 2 and 3 + √7.
f(x) = x³ - 8x² + 14x - 4

Answer

Polynomial Function:

To write a polynomial function with the given zeros 2 and 3 + √7, we must also include the conjugate of 3 + √7, which is 3 - √7, to ensure the coefficients are rational.

The polynomial is formed by multiplying the factors corresponding to each zero:

  1. (x - 2)
  2. (x - (3 + √7))
  3. (x - (3 - √7))

Multiply these factors:

(x - 2) [(x - 3) - √7][(x - 3) + √7]

Using the difference of squares:

(x - 2) [(x - 3)² - (√7)²]

(x - 2) [(x - 3)² - 7]

Expand (x - 3)²:

(x - 2) [x² - 6x + 9 - 7]

(x - 2) [x² - 6x + 2]

Expand the product:

x(x² - 6x + 2) - 2(x² - 6x + 2)

x³ - 6x² + 2x - 2x² + 12x - 4

Combine like terms:

x³ - 8x² + 14x - 4

Thus, the polynomial function is:

f(x) = x³ - 8x² + 14x - 4

Have a similar question?

Snap a photo of your homework and get a step-by-step answer in seconds. You can ask follow-up questions until it makes sense.

Solve my question free Math help Find a math tutor

More math questions